DUAL LINEAR POLARIZED FOLDED STACKED PATCH/MAGNETOELECTRIC ANTENNA FOR COMPACT ANTENNA ARRAY ARRANGEMENTS

Systems, devices, and methods related to dual linear polarized wideband antennas for compact antenna arrangements are provided. An example antenna structure includes a multi-layered printed circuit board (PCB); a folded magnetoelectric antenna element including a first portion disposed on a first layer of the multi-layered PCB and a first fold portion contiguous to the first portion and extending to at least a second layer of the multi-layered PCB; and a patch antenna element disposed on a third layer of the multi-layered PCB, wherein the first, second, and third layers are separate layers of the multi-layered PCB. The antenna structure further includes a first feeding port electrically coupled to the patch antenna element, and a second feeding port electrically coupled to the patch antenna element, where the first and second feeding ports are associated with different polarizations.

TECHNICAL FIELD OF THE DISCLOSURE

The present disclosure generally relates to electronics and, more particularly, to antennas used in radio frequency (RF) systems.

BACKGROUND

RF systems are systems that transmit and receive signals in the form of electromagnetic waves with a frequency range of approximately 3 kilohertz (kHz) to 300 gigahertz (GHz). RF systems are commonly used for wireless communications, with cellular/wireless mobile technology being a prominent example.

In the context of RF systems, an antenna is a device that serves as the interface between radio waves propagating wirelessly through space and electric currents moving in metal conductors used with a transmitter or receiver. During transmission, a radio transmitter supplies an electric current to the antenna’s terminals, and the antenna radiates the energy from the current as radio waves. During reception, an antenna intercepts some of the power of a radio wave to produce an electric current at its terminals, where the electric current is subsequently applied to a receiver to be amplified. Antennas are essential components of all radio equipment, and are used in radio broadcasting, broadcast television, two-way radio, communications receivers, radar, cell phones, satellite communications and other devices.

An antenna with a single antenna element may broadcast a radiation pattern that radiates equally in all directions in a spherical wavefront. Phased array antennas may generally refer to a collection of antenna elements that are used to focus electromagnetic energy in a particular spatial direction, thereby creating a main beam. Phased array antennas may offer numerous advantages over single antenna systems, such as high gain, ability to perform directional steering, and simultaneous communication. Therefore, phased array antennas may be used more frequently in a myriad of different applications, such as in military applications, mobile technology, on airplane radar technology, automotive radars, cellular telephone and data, and Wi-Fi technology.

DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE DISCLOSURE

Overview

The systems, methods and devices of this disclosure each have several innovative embodiments, no single one of which is solely responsible for all of the desirable attributes disclosed herein. Details of one or more implementations of the subject matter described in this specification are set forth in the description below and the accompanying drawings.

As described above, phased array antennas may generally refer to a collection of antenna elements that are used to focus RF energy in a particular direction, thereby creating a main beam. In particular, the individual antenna elements of a phased array antenna may radiate in a spherical pattern, but, collectively, a plurality of such antenna elements may be configured to generate a wavefront in a particular spatial direction through constructive and destructive interference. The relative phases of the signal transmitted at each antenna element can be either fixed or adjusted, allowing the antenna system to steer the wavefront in different spatial directions. In an example, a phased array antenna system may include an oscillator, a plurality of antenna elements, a phase adjuster or shifter, a variable gain amplifier, a receiver, and a control processor. The phased array antenna system may use the phase adjusters or shifters to control the phase of the signal transmitted by each of one or more of its antenna elements. The radiated patterns of the antenna elements may constructively interfere in a target direction creating a wavefront in that direction called the main beam (also referred to as “lobe”). In this way, the phased array antennas can realize increased gain and improve signal to interference plus noise ratio in the direction of the main beam. The radiation pattern may destructively interfere in several other directions other than the direction of the main beam and thus can reduce gain in those directions.

“Beam scanning” may refer to changing (i.e., scanning) the direction of the main beam of an antenna element. In this context, the term “broadside” refers to the direction of the main beam that is perpendicular to the plane of the antenna element. With fifth generation cellular (5G) (e.g., millimeter-wave (mm-wave) technology) applications, there is a need for aggressive scan angles that might go up to at least 70 degrees away from the broadside (in the following, the term “scan angle” refers to the angle between the direction of the main beam of an antenna element and the broadside).

In an example, a phased antenna array may include a plurality of antenna elements arranged in one or more columns and one or more rows spaced apart from each other on a printed circuity board (PCB) or any suitable support structure. To provide a wide or large scanning angle, the inter-element pitch between adjacent antenna elements is to be small (e.g., about half of a resonant wavelength). As such, a wide or large scan angle antenna array may include closely spaced antenna elements. Further, in some examples, it may be desirable to have a certain inter-element spacing or gap to reduce or avoid coupling (mutual coupling) between antenna elements and/or allow room for assembly (e.g., when the antenna elements are individual surface mount technology (SMT) components). That is, to achieve a large scan angle, it may be desirable to design antenna elements with a size (or dimension) as small as possible so that they can fit into a wide scan range antenna array. However, an antenna element of a smaller size may support a narrower bandwidth. Accordingly, it may be challenging to design antennas or antenna elements that are small enough to fit into an antenna array that can provide a wide scan range while also supporting a wide bandwidth. A wideband antenna may refer to an antenna that can cover a frequency band of interest with a fractional bandwidth of about 9% to about 25%, where a fractional bandwidth may be defined as the absolute bandwidth divided by the center frequency. A wide scan angle or wide scan range antenna array may refer to an antenna array that can provide a scan angle up to about 70 degrees in both the azimuth direction and the elevation direction.

Further, some RF systems may desire to utilize dual linear polarized antennas for transmissions and/or receptions. For instance, a wireless communication system (e.g., a 5G system) may transmit or receive two independent data streams at the same time using two orthogonalized polarized signals (e.g., one in a horizonal (H)-polarization and another in a vertical (V)-polarization) to increase system throughput. Alternatively, a wireless communication system may transmit or receive the same data stream using two orthogonalized polarized signals for diversity gain. A V-polarization may refer to the oscillation of an antenna’s electrical field in a vertical plane and an H-polarization may refer to the oscillation of the antenna’s electrical field in a horizontal plane perpendicular to the vertical plane.

The present disclosure provides compact, wideband, dual linear polarized antenna structures or elements that can fit into a wide scan range antenna array. The disclosed antenna structures or elements are based on a combination (or “fusion”) of folded magnetoelectric antenna and patch antenna arranged (e.g., printed) on a multi-layered PCB. The magnetoelectric antenna can operate over a wide bandwidth while the folding of the magnetoelectric antenna reduces the dimension of the antenna structures so that the antenna structures are small enough (in size) to fit as radiating elements in wide scan range phased antenna arrays. The patch antenna may serve as a symmetric driver that can be excited by direct probes or cross-slots to provide dual linear polarization. In one aspect of the present disclosure, an example antenna structure may include a multi-layered PCB with a folded magnetoelectric antenna element and a patch antenna element. The multi-layered PCB may include layers that are stacked vertically. The folded magnetoelectric antenna element may include a plurality of patches disposed on a first layer (e.g., a top layer) of the multi-layered PCB, for example, to form electric dipoles. Further, each magnetoelectric antenna patch may be shorted to a ground layer of the multi-layered PCB to form magnetic dipoles. One or more edges (or extents) of each patch of the plurality of patches may be folded (to reduce the dimension of the antenna structure) and may extend vertically to at least a second layer of the multi-layered PCB. As an example, a first patch of the plurality of patches may include a first portion (e.g., a planar portion) disposed on the first layer, a first fold portion contiguous to the first portion and extends vertically towards the second layer, and a second fold portion contiguous to the first fold portion and disposed on the second layer. The patch antenna element may be disposed on a third layer of the multi-layered PCB. The first, second, and third layers are separate layers of the multi-layered PCB, where the second layer may be vertically below the first layer, and the third layer may be vertically below the second layer.

In some aspects, to further reduce the dimension of the antenna structure, the first fold portion of the first patch (of the magnetoelectric antenna element) may further extend to the third layer of the multi-layered PCB. When the first fold portion is extended to the third layer, the first patch can further include a third fold portion contiguous to the first fold portion and disposed on the third layer.

In some aspects, an outer edge of the first patch (of the magnetoelectric antenna element) may be folded to form the first fold portion. That is, the first fold portion may extend along a side of the antenna structure. In some aspects, an inner edge of the first patch is folded to form the first fold portion. That is, the first fold portion may extend vertically within the antenna structure (e.g., along a middle plane of the antenna structure). In some aspects, both the outer edge and the inner edge of the first patch can be folded. In some aspects, each of the plurality of patches (of the magnetoelectric antenna element) may be folded at one or more outer edges and/or at one or more inner edges. In an example, the number of patches in the plurality of patches may be 4, and each patch may be disposed on a different quadrant of the first layer and spaced apart from each other. A parasitic capacitance may be formed from the spaced apart magnetoelectric antenna patches. The folding at the inner edges of the patches increases the capacitance area, thereby increasing the capacitance of the magnetoelectric antenna element. The resonant frequency of an antenna is inversely proportional to the square root of its capacitance. As such, the increase of the capacitance from the folding at the inner edges of the patches can lower the resonant frequency of the magnetoelectric antenna element without increasing the dimension of the antenna structure.

In some aspects, each of the plurality of patches (of the magnetoelectric antenna element) may be connected to the ground layer of the multi-layered PCB by at least two staggered vias (e.g., electrical connection elements). For instance, a first via may extend from the first layer of the multi-layered PCB to the second layer of the multi-layered PCB, and a second via may extend from the second layer to the ground layer.

In some aspects, the antenna structure may include a first feeding port and a second feeding port electrically coupled to the patch antenna element, where the first feeding port may be associated with a first polarization (e.g., H-polarization) and the second feeding port may be associated with a second polarization (e.g., V-polarization) different from the first polarization. To provide symmetric dual polarization, each of the first feeding port and the second feeding port may be positioned symmetrically (e.g., at about a middle location) along a corresponding edge or side of the antenna structure. In this way, the antenna structure can be positioned in any orientation (e.g., with arbitrary assembly rotation) and still provide the same dual polarization performance.

In some aspects, a side dimension of the folded magnetoelectric antenna element may be between about 0.25 of a wavelength and about 0.3 of a wavelength. In some aspects, the layers of the multi-layered PCB may be spaced apart from each other by dielectric material having a dielectric constant between about 3 and about 4. In some aspects, the multi-layered PCB may include a PCB core that separates the first, second, and third layers from ground layer(s) of the PCB, where the PCB core can have a height between about 0.05 of a free-space wavelength and about 0.2 of a free-space wavelength. In some aspects, it may be desirable to arrange the PCB layers to be symmetrical around the PCB core (e.g., to prevent warping during assembly and allow for mass-manufacturability). To that end, the multi-layered PCB may include a fourth, a fifth, and a sixth layers spaced apart from the first, second, and third layers by the PCB core.

In a further aspect of the present disclosure, a phased antenna array apparatus may include a plurality of antenna elements, each constructed with a folded magnetoelectric antenna element and a patch antenna element arranged (or printed) on a multi-layered PCB as discussed herein. The folding of the magnetoelectric antenna element (e.g., at the inner edge(s) and/or outer edge(s) of the patches) can reduce the size or side dimension of the antenna elements so that the antenna elements can be arranged closed to each other (e.g., with a pitch of half of a resonant wavelength or less) at the array to provide a wide scan range (e.g., with an azimuth scan angle up to about ± 70 degrees and an elevation scan angle up to about ± 70 degrees).

The systems, schemes, and mechanisms described herein advantageously provides compact, wideband antenna structures based on a folded magnetoelectric antenna element and a patch antenna element stacked and printed on a multi-layered PCB. The compact footprint enables the antenna structures to be fitted into a wide scan range antenna array. That is, the disclosed antenna structure is suitable for use to provide wideband, wide scan range antenna arrays. For example, the disclosed antenna structure may have a side dimension between about 0.25 to about 0.3 of a resonant wavelength and may provide a fractional bandwidth up to about 25%, and may fit into a phase antenna array that provides a scan angle up to about 70 degrees in both azimuth and elevation. Additionally, folding inner edges of the patches of the magnetoelectric antenna element can lower a resonant frequency of an antenna element without increasing the dimension or footprint of the antenna element. Further, utilizing a symmetric feeding structure (the symmetric excitation for dual polarization) with the patch antenna element can enable the disclosed antenna structures to provide symmetric radiation patterns for H-polarization and V-polarization. This can advantageously allow for arbitrary assembly rotation of these antenna elements without impacting dual polarization performance. The disclosed antenna structures may be suitable for use in a printed antenna array or an SMT antenna array and may be compatible with high-volume manufacturing (HVM) capabilities.

Example Antenna Arrays

FIG.1illustrates an exemplary antenna array arrangement100. The antenna array arrangement100may be suitable for use in an RF system for wireless transmission and/or reception. The antenna array arrangement100may also be used in conjunction with phase shifters to provide beam steering (e.g., as shown in the antenna apparatus800ofFIG.8). As shown inFIG.1, the antenna array arrangement100is a printed antenna array including a plurality of antenna elements112printed on a PCB110. The antenna elements112may be arranged in columns and rows and spaced apart from each other. For simplicity,FIG.1illustrates the printed antenna array as a 3-by-5 antenna array (e.g., with antenna elements112arranged in 3 rows and 5 columns). However, a printed antenna array can include any suitable number of antenna elements (e.g., about 4, 8, 16, 64, 256, 1024 or more) and may be arranged in any suitable configuration. The PCB110may be a structure with alternating conductive layers (e.g., made of conductive materials such as copper) and insulating layers (e.g., made of dielectric materials). A conductive layer may include patterns of conductive traces (e.g., flat narrow tracks of conductors) to provide electrical connections on that layer and/or patterns of antennas elements as shown. In general, a PCB may have any suitable number of conductive layers (e.g., about 2, 3, 4, 5 6, 7, 8, 9, 10, 11, 12 or more).

To achieve a wide scan angle, the inter-element pitch104(e.g., represented by P) may be half a resonant wavelength (e.g., represented by λ0). That is, the antenna elements112may have a small size and may be arranged close to each other in a wide scan angle antenna array. Further, it may be desirable to arrange the antenna elements112with a certain inter-element spacing or gap102(e.g., represented by G) to reduce or avoid mutual coupling (parasitic coupling) between adjacent elements112. In some examples, the inter-element spacing or gap (e.g., the gap102) in a printed antenna array may be limited by the shape-to-shape spacing from a manufacturing point of view.

FIG.2illustrates an exemplary antenna array arrangement200. The antenna array arrangement200may be suitable for use in an RF system for wireless transmission and/or reception. The antenna array arrangement200may also be used in conjunction with phase shifters to provide beam steering (e.g., as shown in the antenna apparatus800ofFIG.8). As shown inFIG.2, the antenna array arrangement200includes a plurality of individual SMT antenna elements212mounted (or soldered) onto a PCB210. The SMT antenna elements212may be arranged in columns and rows and spaced apart from each other. For simplicity,FIG.2illustrates the SMT antenna array as a 3-by-5 antenna array (e.g., with antenna elements212arranged in 3 rows and 5 columns). However, an SMT antenna array can include any suitable number of antenna elements (e.g., about 4, 8, 16, 64, 256, 1024 or more) and may be arranged in any suitable configuration. The PCB210may be substantially similar to the PCB110. To support the mounting or soldering of the SMT antenna elements212, the PCB210can further include conductive pads to accept component terminals.

Similar to the arrangement100, to achieve a wide scan angle, the antenna elements212are to be small in size so that they can be arranged with a small inter-element pitch204, (e.g., of about λ0/2). Further, it may be desirable to arrange the antenna elements212with a certain inter-element spacing or gap202(e.g., represented by G) to reduce or avoid mutual coupling between adjacent elements212. In some examples, the inter-element spacing or gap (e.g., the gap202) in an SMT antenna array may be limited by the assembly clearance capability and/or SMT component packaging guidelines or rules. In some examples, the gap202may be at least 1.5 millimeter (mm) to allow for assembly of the antenna elements212onto the PCB210.

As discussed above, the operating bandwidth of an antenna element may be dependent on its size where the larger the antenna element size, the wider its operating bandwidth. For printed antenna arrays such as the antenna array arrangement100, the antenna elements can extend laterally. For instance, a printed antenna array can include stacked patched, magnetoelectric antennas having a sufficiently large size to provide wide bandwidth operations. However, this can increase the footprint and thus may not allow the antenna array to operate over a wide scan range. For SMT antenna array such as the antenna array arrangement200, the antenna elements can extend vertically. For instance, an SMT antenna array can be constructed from dielectric resonator antennas (e.g., ceramic based antennas). However, the vertical extension may cause the SMT antenna component to exceed the dimension (e.g., height) allowed by SMT packaging guidelines or rules. Hence, magnetoelectric antennas may have limited usability for wideband SMT antennas.

Further, as mentioned above, some RF systems may desire to utilize dual linear polarized antennas for transmissions and/or reception. While stacked patch antennas can support symmetric excitation for dual polarization and operate over a wide bandwidth, the wide bandwidth capability may be loss when stacked patch antennas are placed in SMT components. This is because a stacked patch antenna may typically have to be truncated (in size, area) in order to be placed in an SMT component. The truncation of stacked patch antennas may cause an undesirable dip (a lower antenna gain) in the middle of the wide bandwidth, thus destroying the wide bandwidth capability. Hence, stacked patch antennas may have limited usability for wideband SMT antennas.

Accordingly, it may be challenging to design printed or SMT antennas or antenna elements that are small enough to fit into an antenna array to provide a wide scan range but also support a wide bandwidth and provide symmetric dual polarization performance.

Example Compact, Wide Band, Dual Linear Polarized Antenna Structures, Elements, and Devices

FIGS.3A and3Bare discussed in relation to each other to illustrate an exemplary wideband antenna structure300with a compact footprint that can fit into an antenna array (e.g., similar to the antenna array arrangements100and/or200) to provide a wide scan angle. As discussed above, a wideband antenna may refer to an antenna that can cover a frequency band of interest with a fractional bandwidth of about 9 % to about 25%. As an example, a 5G system a center frequency at about 30 GHz (e.g., N257, N258, and/or N259 bands) with a bandwidth of about 3 GHz. That is, a fractional bandwidth of about 10%.

FIG.3Ais a cross-sectional view of the compact, wideband antenna structure300, according to some embodiments of the present disclosure.FIG.3Bis a perspective view of the compact, wideband antenna structure300, according to some embodiments of the present disclosure. The antenna structure300may be suitable for use in an RF system for wireless transmission and/or reception. In some examples, the antenna structure300may be part of a phased antenna array (e.g., the antenna array arrangements100and/or200), which may be used in conjunction with phase shifters to provide beam steering (e.g., as shown in the antenna apparatus800ofFIG.8). The cross-sectional view ofFIG.3Amay be taken along the line303ofFIG.3B.

As shown inFIG.3A, the antenna structure300includes a folded magnetoelectric antenna element301and a patch antenna element320. The folded magnetoelectric antenna element301and the patch antenna element320may be printed on a multi-layered PCB. The multi-layered PCB may include a plurality of conductive layers (e.g., at least a first layer302, a second layer304, a third layer306, and a fourth layer308) spaced apart from each other by dielectric materials and stacked vertically (e.g., along a direction of the z-axis). For simplicity,FIG.3Aonly illustrate the conductive layers (the first layer302, the second layer304, the third layer306, and the fourth layer308) and not the dielectric or insulating layers. A more detailed structure of the multi-layered PCB is shown and discussed below with reference toFIG.6.

The folded magnetoelectric antenna element301may include a plurality of patches310(shown as310-1and310-2) spaced apart from each other by a gap311to form electric dipoles and each magnetoelectric antenna patch310may be electrically coupled (or shorted) to a ground potential or ground layer340(e.g., the fourth layer308) of the multi-layered PCB to form magnetic dipoles. Mechanisms for shorting or connecting the patches310to ground will be discussed more fully below with reference toFIG.3B. In some aspects, the folded magnetoelectric antenna element301may include four patches310, each located at a different quadrant of the first layer302(e.g., as shown inFIG.5C). The magnetoelectric antenna patches310may be made of any suitable electrically conductive material. To reduce the size or a side dimension of the magnetoelectric antenna element301, one or more outer edges (or extents) of each magnetoelectric antenna patch310may be folded and may extend vertically to at least the second layer304of the multi-layered PCB. When each patch310has a square shape or rectangular shape and located in a different quadrant of the first layer302, each patch may include two adjacent outer edges (each extending along a side of the first layer302of the antenna structures300) and two adjacent inner edges (each extending from a side of the first layer302towards the center of the first layer302).

InFIG.3A, the cross-sectional view shows a first magnetoelectric antenna patch310-1and a second magnetoelectric antenna patch310-2. For simplicity, only portions of the first magnetoelectric antenna patch310-1are labeled inFIG.3Aand described below. However, analogous descriptions may be applied to other magnetoelectric antenna patches310(e.g., the second magnetoelectric antenna patch310-2). As shown, the first magnetoelectric antenna patch310-1includes a first portion312-1, a first fold portion312-2, and a second fold potion312-3. The first portion312-1may be disposed (e.g., printed) on the first layer302and may have a square shape or a rectangular shape. The first fold portion312-2may be contiguous to the first portion312-1and may extend vertically to the second layer304along a direction of the z-axis. The second fold portion312-3may be contiguous to the first fold portion312-2and disposed (e.g., printed) on the second layer304. In other words, a first outer edge or outer extent314of the first magnetoelectric antenna patch301-1is folded along a side of the antenna structure300to form the first fold portion312-2(a vertical fold portion) and the second fold portion312-3(a horizonal fold portion which may also be referred to as a folded magnetoelectric antenna arm). The folding with the first fold portion312-2and the second fold portion312-3may be referred to as 2X folding. In a similar way, an outer edge or outer extent the second magnetoelectric antenna patch310-2may be folded along a side of the antenna structure300. Thus, the antenna length (or resonant length) (e.g., Lr) of the magnetoelectric antenna element301may include not only the side dimension316(e.g., L1) but also additional lengths from the fold portions of the magnetoelectric antenna patches310-1and310-2. For instance, the vertical fold portion312-2of the first magnetoelectric antenna patch310-1has a length318(e.g., L2), the horizontal portion312-3of the first magnetoelectric antenna patch310-1has a length317(e.g., L3), and the second magnetoelectric antenna patch310-2has similar fold portions with similar lengths as the first magnetoelectric antenna patch310-1. As such, the antenna length Lr may be L1+2×(L2+L3).. That is, the magnetoelectric antenna element301may have an effective radiating length Lr longer than the side dimension316(which may correspond to a side dimension of the antenna structure300) . Accordingly, the folding enables the magnetoelectric antenna element301to support a wide bandwidth with a compact footprint.

The patch antenna element320may be disposed (e.g., printed) on the third layer306. The patch antenna element320is formed from electrically conductive materials. Further, the patch antenna element320can have any suitable shape. In one example, the patch antenna element320may be a rectangular patch antenna. In another example, the patch antenna element320may be a square patch antenna. In yet another example, the patch antenna element320may be microstrip antenna. In some examples, it may be more suitable for the patch antenna element320to have a square shape so that the patch antenna element320may serve as a symmetric driver that can be excited by direct probes or cross-slots to provide symmetric dual linear polarization performance. To that end, the patch antenna element320may be coupled to a feeding element330that electrically connects the patch antenna element320to a feeding port extending from the ground layer340. The feeding element330may be associated with one of a H-polarization or a V-polarization. The antenna structure300may have another feeding element similar to the feeding element330, where the other feeding element may be associated with the other one of the H-polarization or the V-polarization as will be discussed more fully below with reference toFIGS.7A and7B.

An RF signal fed via the feeding element330may excite or cause the patch antenna element320(driver) to emanate electromagnetic field. While the patch antenna element320is not electrically coupled to the folded magnetoelectric antenna element301, the electromagnetic field emanated from the driver patch antenna element320may cause the magnetoelectric antenna element301to be parasitically excited (to emanate electromagnetic field). In some instances, the impedance bandwidth of the antenna structure300may be dependent on the separation between the patch antenna element320and the magnetoelectric antenna patches310. In some instances, the folded magnetoelectric antenna element301may be referred to as a top patch and the patch antenna element320may be referred to as a bottom patch.

Referring toFIG.3B, the perspective view of the antenna structure300shows only half of the folded magnetoelectric antenna element301(including the first magnetoelectric antenna patch310-1and the second magnetoelectric antenna patch310-2) in order to provide a better view of the internal structure of the antenna structure300. Similar toFIG.3A, for simplicity, only portions of the first magnetoelectric antenna patch310-1are labeled inFIG.3Band described below. However, analogous descriptions may be applied to other magnetoelectric antenna patches310(e.g., the second magnetoelectric antenna patch310-2) of the folded magnetoelectric antenna element301. In the illustrated example ofFIG.3B, the first fold portion312-2of the first magnetoelectric antenna patch310-1is shown as a via (of electrically conductive material) connecting the first portion312-1to the second fold portion312-3. However, in other examples, the first fold portion312-2may be formed using edge plating (e.g., a copper plating that runs from the first layer302to the second layer304along a side of the antenna structure300).

As further shown inFIG.3B, a second outer edge or outer extent315of the first magnetoelectric antenna patch310-1may also be folded to form a fold portion (e.g., similar to the fold portion312-2) shown by312-7that is contiguous to the first portion312-1and extending to the second layer304and another fold portion (e.g., similar to the second fold portion312-3) disposed on the second layer304.

As further shown inFIG.3B, the antenna structure300may include vias350connecting the magnetoelectric antenna patches310to the ground layer340. More specifically, each magnetoelectric antenna patch310may be shorted to the ground layer340by a via350located near the inner edge of the respective magnetoelectric antenna patch310. The patch antenna element320may include openings or through holes322so that the vias350may extend from the first layer302(where the patches310are disposed) to the ground layer340. In some examples, each via350may include two or more staggered vias as will be discussed more fully below with reference toFIGS.5C-5F. As can be seen inFIG.3B, the folds of the magnetoelectric antenna element301at the outer extent (e.g., the outer extent315) are separate from the vias350that electrically connects the magnetoelectric antenna element301to ground to provide the magnetic dipoles.

FIGS.4A and4Bare discussed in relation to each other to illustrate an exemplary wideband antenna structure400with a compact footprint that can fit into an antenna array (e.g., similar to the antenna array arrangements100and/or200) to provide a wide scan angle. Similar toFIGS.3A-3B, only portions of the first magnetoelectric antenna patch310-1are labeled inFIGS.4A and4Band described below. However, analogous descriptions may be applied to other patches310(e.g., the second magnetoelectric antenna patch310-2) of the folded magnetoelectric antenna element301.

FIG.4Ais a cross-sectional view of the compact, wideband antenna structure400, according to some embodiments of the present disclosure.FIG.4Bis a perspective view of the compact, wideband antenna structure400, according to some embodiments of the present disclosure. The antenna structure400may be suitable for use in an RF system for wireless transmission and/or reception. In some examples, the antenna structure400may be part of a phased antenna array (e.g., the antenna array arrangements100and/or200), which may be used in conjunction with phase shifters to provide beam steering (e.g., as shown in the antenna apparatus800ofFIG.8). The cross-sectional view ofFIG.4Amay be taken along the line403ofFIG.4B. The antenna structure400shares many elements with the antenna structure300ofFIGS.3A-3B; for brevity, a discussion of these elements is not repeated, and these elements may take the form of any of the embodiments disclosed herein.

As shown inFIG.4A, the antenna structure400may be substantially similar to the antenna structure300. However, the antenna structure400can provide a more compact footprint than the antenna structure300. To that end, a larger portion or extent414of the magnetoelectric antenna element301may be folded compared to the folding at the antenna structure antenna structure300. More specifically, the first magnetoelectric antenna patch310-1may include a first portion412-1(similar to the portion312-1) disposed on the first layer302, a first fold portion412-2(similar to the portion312-2) contiguous to the first portion412-1, and a second fold portion412-3(similar to the portion312-3) contiguous to the first portion412-1and disposed on the second layer304. However, the first fold portion412-2may extend vertically (e.g., along a direction of the z-axis) further to the third layer. As such, the first fold portion412-1of the magnetoelectric antenna element301in the antenna structure400may have a length418longer than the length318ofFIG.3. Hence, the magnetoelectric antenna element301in the antenna structure400may have a side dimension416shorter than the side dimension316of the magnetoelectric antenna element301in the antenna structure300. Further, the first magnetoelectric antenna patch310-1may include a third fold portion412-4(another horizontal fold portion) contiguous to the first fold portion412-2and disposed (e.g., printed) on the third layer306. The third fold portion412-4may be spaced apart from the patch antenna element320that is also disposed on the third layer306. In some instances the third fold portion412-4may have the same length (e.g., the length417, L3) as the second fold portion412-3as shown. In other instances, the third fold portion412-4may have a longer length or a shorter length than the second fold portion412-3. The folding with the first fold portion412-2, the second fold portion412-3, and the third fold portion412-4may be referred to as 3X folding.

Similar to the antenna structure300, the antenna length (or resonant length) (e.g., Lr) of the magnetoelectric antenna element301of the antenna structure400may include not only the side dimension416(e.g., L1) but also additional lengths from the fold portions of the magnetoelectric antenna patches310-1and310-2. For instance, the vertical fold portion412-2of the first magnetoelectric antenna patch310-1has a length418(e.g., L2), each of the horizontal portions412-3and412-4of the first magnetoelectric antenna patch310-1has a length417(e.g., L3), and the second magnetoelectric antenna patch310-2has similar fold portions with similar lengths as the first magnetoelectric antenna patch310-1. As such, the antenna length Lr for the antenna structure400may be L1+2×(L2+L3+L3).

Referring toFIG.4B, the perspective view of the antenna structure400shows only half of the folded magnetoelectric antenna element301(including the first magnetoelectric antenna patch310-1and the second magnetoelectric antenna patch310-2) in order to provide a better view of the internal structure of the antenna structure400. Similar toFIG.3B, the first fold portion412-2of the first magnetoelectric antenna patch310-1is shown as a via (of electrically conductive material) connecting the first portion412-1to the second fold portion412-3. However, in other examples, the first fold portion412-2may be formed using edge plating (e.g., a copper plating that runs from the first layer302to the third layer306along a side of the antenna structure300). Further, a second outer edge or outer extent415of the first magnetoelectric antenna patch310-1may be folded in a similar way to form portions similar to the fold portions412-2,412-3,412-4.

FIGS.5A-5Fare discussed in relation to each other to illustrate an exemplary wideband antenna structure500with a compact footprint that can fit into an antenna array (e.g., similar to the antenna array arrangements100and/or200) to provide a wide scan angle. Similar toFIGS.3A-3B and4A-3B, only portions of the first magnetoelectric antenna patch310-1are labeled inFIGS.5A-5Fand described below. However, analogous descriptions may be applied to other patches310(e.g., the second magnetoelectric antenna patch310-2) of the folded magnetoelectric antenna element301.

FIG.5Ais a cross-sectional view of the compact, wideband antenna structure500, according to some embodiments of the present disclosure.FIG.5Bis a perspective view of the compact, wideband antenna structure500, according to some embodiments of the present disclosure. The antenna structure500may be suitable for use in an RF system for wireless transmission and/or reception. In some examples, the antenna structure500may be part of a phased antenna array (e.g., the antenna array arrangements100and/or200), which may be used in conjunction with phase shifters to provide beam steering (e.g., as shown in the antenna apparatus800ofFIG.8). The cross-sectional view ofFIG.5Amay be taken along the line503ofFIG.5B. The antenna structure500shares many elements with the antenna structure400ofFIGS.4A-4B; for brevity, a discussion of these elements is not repeated, and these elements may take the form of any of the embodiments disclosed herein.

As shown inFIG.5A, the antenna structure500may be substantially similar to the antenna structure 400. However, in the antenna structure500, the magnetoelectric antenna element301is further folded at an inner edge or inner extent513of the magnetoelectric antenna element301in addition to the folding at an outer edge or outer extent514of the magnetoelectric antenna element301. The additional folding at the inner extent513can reduce a side dimension of the antenna structure500further and/or lower a resonant frequency (e.g., represented by f0) of the magnetoelectric antenna element301. More specifically, the first magnetoelectric antenna patch310-1may include a first portion512-1(similar to the portions312-1and412-1) disposed on the first layer302, a first fold portion512-2(similar to the portions312-2and412-2) contiguous to the first portion512-1and extending vertically to the third layer306, a second fold portion512-3(similar to the portions312-3and412-3) contiguous to the first portion512-1and disposed on the second layer304, and a third fold portion512-4(similar to the portions412-4) contiguous to the first portion512-1and disposed on the third layer306. Further, the first magnetoelectric antenna patch320-1may include a fourth, vertical fold portion512-5(at an inner edge of the first magnetoelectric antenna patch310-1) contiguous to the first portion512-1and extending vertically to the second layer304along a direction of the z-axis, and a fifth, horizontal fold portion512-6contiguous to the fourth fold portion512-5and disposed (e.g., printed) on the second layer304. The fifth, horizontal fold portion512-6may have any suitable length519. For instance, the fifth, horizontal fold portion512-6can have the same length, a longer length, or a shorter length compared to the second fold portion512-3and/or the third portion512-4. In a similar way, the second magnetoelectric antenna patch310-2may be further folded at an inner edge in addition to the folding at an outer edge.

A parasitic capacitance502represented by Cp may be formed between the spaced apart magnetoelectric patches310-1and310-2. In antennas, the larger the capacitance, the lower the resonant frequency. Typically, the surface area of an antenna may be enlarged to increase the capacitance of the antenna. Here, in the antenna structure500, the increase in capacitance surface area is provided by the fourth fold portion512-5of the first magnetoelectric antenna patch320-1and a similar fold portion of the second patch320-2. That is, the equivalent parasitic capacitance502between the magnetoelectric patches310-1and310-2may be increased through the inner edge folding. Accordingly, the antenna structure500may lower the resonant frequency without increasing a dimension of the antenna structure500and/or reducing the spacing between the inner extents of the magnetoelectric patches310-1and310-2. In some instances, the parasitic capacitance502formed from the inner edge folding may be referred to as a folded inner or middle capacitance.

Similar to the antenna structures300and400, the antenna length (or resonant length) (e.g., Lr) of the magnetoelectric antenna element301of the antenna structure500may include not only the side dimension516(e.g., L1) but also additional lengths from the fold portions of the magnetoelectric antenna patches310-1and310-2. For instance, the vertical fold portion512-2of the first magnetoelectric antenna patch310-1has a length518(e.g., L2), each of the outer horizontal portions512-3and512-4of the first magnetoelectric antenna patch310-1has a length517(e.g., L3), the inner horizontal portion516-6of the first magnetoelectric antenna patch310-1has a length519(e.g., L4), and the second magnetoelectric antenna patch310-2has similar fold portions with similar lengths as the first magnetoelectric antenna patch310-1. As such, the antenna length Lr for the antenna structure500may be L1+2×(L2+L3+L3+L4).

Referring toFIG.5B, the perspective view of the antenna structure500shows only half of the folded magnetoelectric antenna element301(including the first magnetoelectric antenna patch310-1and the second magnetoelectric antenna patch310-2) in order to provide a better view of the internal structure of the antenna structure500. Similar toFIGS.3B and4B, the first fold portion512-2of the first magnetoelectric antenna patch310-1is shown as a via (of electrically conductive material) connecting the first portion512-1to the second fold portion512-3. Further, the fourth fold portion512-5(at the inner edge) of the first magnetoelectric antenna patch310-1is shown as a via connecting the first portion512-1to the fifth fold portion512-6. However, in other examples, at least one of the first fold portion512-2may be formed using edge plating (e.g., a copper plating that runs from the first layer302to the third layer306) or the fourth fold portion512-5may be formed using edge plating (e.g., a copper plating that runs from the first layer302to the second layer304of the multi-layered PCB). In a similar way, a second outer edge or outer extent515of the first magnetoelectric antenna patch310-1may be folded to form fold portions similar to the fold portions512-2,512-3,512-4and/or a second inner edge of the first magnetoelectric antenna patch310-1may be folded to form fold portions similar to the fold portions512-5and512-6.

As further shown inFIG.5B, the antenna structure500may include a first feeding element550-1and a second feeding element550-2to provide dual polarization excitation. The feeding element550-1may correspond to the feeding element330shownFIG.5A. One of the feeding elements550-1or550-2may be used to feed a signal for transmission in an H-polarization, and the other one of the feeding elements550-1or550-2may be used to feed a signal for transmission in a V-polarization. The dual polarization feeding structure will be discussed more fully below with reference toFIGS.5C-5F and7-8.

FIGS.5C-5Fprovide a more detailed view of the arrangement of the folded magnetoelectric antenna element301, the patch antenna element320, the vias350, and the feeding elements550in the antenna structure500.FIG.5Cis a top view of the first layer302of the antenna structure500, according to some embodiments of the present disclosure. As shown inFIG.5A, each of the patches310-1FIG.5Dis a top view of the second layer304of the antenna structure500, according to some embodiments of the present disclosure.FIG.5Eis a top view of the third layer306of the antenna structure500, according to some embodiments of the present disclosure.FIG.5Fis a top view of the fourth layer308of the antenna structure500, according to some embodiments of the present disclosure.

In some aspects, the antenna structure500may be arranged (e.g., printed) on a multi-layered PCB with six conductive layers, for example, including the first layer302, the second layer304, the third layer306, and the fourth layer308as discussed above, and further include a fifth layer vertically below the fourth layer308, and a sixth layer vertically below the fifth layer (e.g., as shown in the multi-layered PCB structure600ofFIG.6). InFIGS.5C-5F, the circle symbols with the diagonal stripe patten may represent vias connecting the first layer302to the second layer304(represented as 1-2), the circle symbols with the checkered patten may represent vias connecting the first layer302to the third layer306(represented as 1-3), the circle symbols with the horizontal stripe patten may represent vias connecting the second layer304to the fifth layer (another ground layer) of the antenna structure500(represented as 2-5), the circle symbols with the vertical stripe patten may represent vias connecting the third layer306to the fourth layer308(represented as 3-4), the circle symbols with the crisscross patten may represent vias connecting the fourth layer308to the fifth layer (represented as 4-5), and the circle symbols with the dashed-line patten may represent vias connecting the fourth layer308to the sixth layer (represented as 4-6). In some instances, the sixth layer may be an LGA layer (e.g., the LGA layer710shown inFIGS.7A and7B). Further, the ring shape symbol with the dotted pattern may represent via pads, and the ring shape symbol with empty filled pattern may represent slots, through holes, or openings (i.e., a discontinuity in conductive material).

Referring toFIG.5C, the folded magnetoelectric antenna element301includes 4 patches310-1,310-2,310-3, and310-4, each with a planar portion (e.g., the portion512-1) disposed on a different quadrant of the first layer302. The outer edges or outer extents of the first magnetoelectric antenna patch310-1are folded to form the vertical fold portions512-2and512-7extending from the first layer302to the third layer306along sides of the antenna structure500. As explained above, the vertical fold portions512-2and512-7may be in the form of vias connecting the first layer302to the third layer306as shown by the circle symbols with the checkered patten. The inner edges or inner extents of the first magnetoelectric antenna patch310-1are also folded to form vertical fold portions512-5and512-8extending from the first layer302to the second layer304internally along vertical planes within the structure500. Similarly, the vertical fold portions512-5and512-8may be in the form of vias connecting the first layer302to the second layer304as shown by the circle symbols with the diagonal stripe patten. As can be seen inFIG.5C, each of the other patches310-2,310-3, and310-4may have similar folds at corresponding outer edges and corresponding inner edges as the first magnetoelectric antenna patch310-1.

Referring toFIG.5D, the outer edges or outer extents of the first magnetoelectric antenna patch310-1are folded where the horizontal fold portions512-3and512-9(the folded magnetoelectric antenna arms) contiguous to corresponding vertical fold portions512-2and512-7, respectively, are disposed on the second layer304. The fold portions512-3and512-9at the outer extents may be contiguous with each other. Further, the inner edges or inner extents of the first magnetoelectric antenna patch310-1are folded where the horizontal fold portions512-6and512-10contiguous to corresponding vertical fold portions512-5and512-8, respectively, are disposed on the second layer304. The fold portions512-6and512-10may be contiguous with each other. As further shown, the horizontal fold portions512-6and512-10(formed from the folding at the inner extent of the first magnetoelectric antenna patch310-1) are spaced apart from the horizontal fold portions512-3and512-9(formed from the folding at the outer extent of the first magnetoelectric antenna patch310-1). Additionally, each of the other patches310-2,310-3, and310-4may have similar folds at corresponding outer edges and corresponding inner edges. Further, the horizonal fold portions (e.g., the portions512-6and512-10) of each of the patches310-1,310-2,310-3, and310-4formed from the folding at corresponding inner extents that are disposed on the second layer304are spaced apart from each other. As explained above, the folding at the inner extents of each of the patches310-1,310-2,310-3, and310-4may increase the parasitic capacitance of the magnetoelectric antenna element301, thereby lowering the resonant frequency of the magnetoelectric antenna element301.

As further shown inFIG.5D, the antenna structure500may include vias560(shown by the circle symbols with the horizontal stripe patten) extending from the second layer304to the fifth layer (e.g., a ground layer). As mentioned above, each magnetoelectric antenna patch310-1,310-2,310-3,310-4may be shorted to ground by staggered vias (e.g., including two or more interconnected vias connecting a corresponding magnetoelectric antenna patch310-1,310-2,310-3,310-4to a ground layer). In the illustrated example, the first magnetoelectric antenna patch310-1is shorted to the ground layer (the fifth layer) by two staggered vias, the via or portion512-5connecting the first layer302to the second layer304and the via560connecting the second layer304to the fifth layer. For example, each via350shown inFIGS.3B,4B, and5Bmay be formed by two staggered vias similar to the vias512-5and560. The use of staggered vias may lengthen the path to ground, and thus may lower the resonant frequency and may work well in conjunction with the increased capacitance502(from the inner folds of the patches310). As can be seen inFIG.5D, each of the other patches310-2,310-3, and310-4may be shorted to the ground layer in a similar manner as the first magnetoelectric antenna patch310-1. In general, each magnetoelectric antenna patch310-1,310-2,310-3,310-4may be shorted to ground by any suitable number of staggered vias (e.g., 3 or more) and in any suitable staggered configuration (e.g., a first via from the first layer302to the third layer306and a second via from the third layer306to the fifth layer).

Referring toFIG.5E, the outer edges or outer extents of the first magnetoelectric antenna patch310-1are folded where horizontal fold portions512-4and512-11contiguous to corresponding vertical fold portions512-2and512-7, respectively, are disposed on the third layer306. As further shown inFIG.5E, the patch antenna element320is disposed at about a central portion of the third layer306and spaced apart from the horizontal fold portions512-4and512-11that are disposed on the same third layer306. Further, the patch antenna element320may include through holes322(the empty filled outer ring) to allow the vias560to extend from the second layer304to the fifth layer.

As further shown inFIG.5E, the patch antenna element320may be electrically connected to the feeding elements550-1and550-2(e.g., in the form of vias shown by the circle symbols with the vertical stripe pattern extending from the third layer306to the fourth layer308). As mentioned above, the patch antenna element320may serve as a symmetric driver that can be excited by direct probes or cross-slots to provide symmetric dual linear polarization performance. To provide symmetric dual linear polarization performance (e.g., about the same radiation pattern for H-polarization and V-polarization), the feeding elements550-1and550-2can be located symmetrically in the antenna structure500. Symmetric dual linear polarization performance may be refer to the performance For example, the feeding element510-1may be located at a distance504away from one side of the patch antenna element320and at a distance505away from another side of the patch antenna element320, and the feeding element510-2may be located at a distance506away from one side of the patch antenna element320and at a distance507away from another side of the patch antenna element320, where the distances504,505,506, and507are about the same. In this way, the antenna structure500may provide about the same performance for the H-polarization and the V-polarization irrespective of any rotation of the antenna structure500that may occur during assembly.

Referring toFIG.5F, the vias560extend from the second layer304to the fifth layer through the fourth layer308. Additionally, the feeding elements550-1and550-2(in the form of vias shown by the circle symbols with the vertical stripe pattern) extend from the third layer306to the fourth layer308. The feeding elements550-1and550-2are further connected to the fifth layer by vias552-1and552-2shown by the circle symbols with the crisscross pattern. The fourth layer308may further include through holes554(openings) at which the feeding element550-2connects to the via552-2and at which the feeding element550-2connects to the via552-2. Further, the fourth layer308can be connected to the sixth layer (e.g., the LGA layer ofFIGS.7and8) by vias shown by the circle symbols with the dashed-line pattern.

WhileFIGS.5C-5Fare described with respect to the antenna structure500, the antenna structures300and400may have substantially similar top views as shown inFIGS.5C-5Fbut some of the fold portions may not be present or may be shorter. For example, the antenna structures300and400may not have the fold portions512-5,512-6,512-8,512-10at the inner extents of the patches310-1,310-2,310-3, and310-4. Further, the magnetoelectric antenna element301in the antenna structure300may include shorter vertical fold portions (e.g., extending from the first layer302to the second layer304and not the third layer306) at the outer extents of the patches310-1,310-2,310-3, and310-4, and thus may not have the horizontal fold portions (e.g., the fold portions512-4and512-11) on the third layer306.

FIG.6is a cross-sectional view of an exemplary multi-layered PCB structure600, according to some embodiments of the present disclosure. In some aspects, the multi-layered PCB structure600may be part of the antenna structure300ofFIGS.3A-3B, part of the antenna structure400ofFIGS.4A-4B, or part of the antenna structure500ofFIGS.5A-5F. For example, the PCB layers302,304,306, and308discussed above are layers of the structure600.

As shown inFIG.6, the multi-layered PCB structure600may include a plurality of conductive layers302,304,306,308,602, and604, a plurality of insulating layers606, and a PCB core608. The conductive layers302,304,306,308,602, and604may be made of any suitable conductive material (e.g., copper). The insulating layers606(e.g., prepreg) and the PCB core608may be made of dielectric materials. In some aspects, the dielectric material may have a dielectric constant between about 3 and about 4. In some aspects, the PCB core608may have a height (or thickness) between about 0.05 and about 0.2 of a free-space wavelength (to have the antenna functional). The top three layers302,304, and306may be signal layers in which the folded magnetoelectric antenna element301and the patch antenna element320are formed as discussed above with reference toFIGS.3A-3B,4A-4B, and5A-5F. The bottom three layers308,602, and604may be ground layers. In some aspects, the last bottom layer604may be an LGA layer as will be discussed more fully below with reference toFIGS.7A-7B. In some aspects, the dielectric antenna height (e.g., including the PCB core608and all the dielectric or insulating layers606) of the multi-layered PCB600may be between about 0.075 and 0.1 of the resonant wavelength.

As further shown inFIG.6, the multi-layered PCB structure600may include vias (electrical connections) to connect one layer to another layer. For example, a via612may connect the first layer302to the third layer306, a via610may connect the fourth layer308to the sixth layer604, a via620may connect the first layer302to the sixth layer604, a via622may connect the second layer304to the fifth layer602, and a via624may connect the third layer306to the fourth layer602. In general, the multi-layered PCB structure600may include any suitable number of vias arranged in any suitable configuration. In some aspects, the vias610and612may be laser vias (e.g., when the vias do not extend across a thick extent of the structure600), and the vias620,622, and624may be mechanical vias (e.g., when the vias extend across a thick extent of the structure600). In some aspects, the mechanical via622may correspond to the via560(the ground shorting via) discussed above with reference toFIGS.5D to5F, and the mechanical via624may correspond to one of the vias or feeding elements550. In some aspects, the laser via612may correspond to the vertical fold portions312-3,412-3,512-3,512-5of the magnetoelectric antenna element301discussed above with reference toFIGS.3A-3B,4A-4B, and5A-5F, respectively.

As further shown inFIG.6, the multi-layered PCB structure600includes a symmetric stack up where the same number of conductive layers are above and below the PCB core608. More specifically, the multi-layered PCB structures600includes three conductive layers302,304, and306on top of the PCB core608and the three conductive layers308,602, and604below the PCB core608. The symmetric stackup can avoid mechanical warpage during manufacturing of the multi-layered PCB structure600. In general, the multi-layered PCB structure600can include any suitable number of conductive layers (e.g., 4, 5, 7, 8, 9, 10, 11, 12 or more) and any stackup configuration.

FIGS.7A and7Bare discussed in relation to each other to illustrate the interface between an SMT antenna element and an LGA.FIG.7Ais a perspective view of an exemplary compact, wideband antenna structure700with an LGA interface, according to some embodiments of the present disclosure.

The antenna structure700is an SMT component with an interface to an LGA layer710. The SMT component may be built from a multi-layered PCB similar to the multi-layered PCB structure600ofFIG.6. The antenna structure700may include a folded magnetoelectric antenna element301(including a plurality of patches310-1,310-2,310-3, and310-4) and a patch antenna element320(not shown) arranged (e.g., printed) on the multi-layered PCB as discussed above with reference toFIGS.3A-3B,4A-4B, or5A-5C. For brevity, a discussion of these elements is not repeated, and these elements may take the form of any of the embodiments disclosed herein.

In some aspects, the LGA layer710may correspond to a sixth layer (e.g., the sixth layer604) of the multi-layered PCB. The LGA layer710may include feeding ports720-1and720-2, where one of the feeding port720-1or720-2may be used to feed a first RF signal (from an RF transceiver) for transmission in an H-polarization, and the other one of the feeding port720-1or720-2may be used to feed a second RF signal (from the RF transceiver) for transmission in a V-polarization. In some aspects, the first and second RF signals may carry different data streams, for example, to increase throughput. In other aspects, the first and second RF signals may carry the same data stream, for example, to increase diversity.

In some aspects, for SMT antennas (e.g., the antenna structure700), the antennas can be designed for the impedance transformed by the package interface (e.g., the LGA layer710or any other package interface). In some instances, the package interface can be matched separately to a single impedance.

FIG.7Bis a top view of the compact, wideband antenna structure700with the LGA interface, according to some embodiments of the present disclosure.FIG.7Billustrates a top view of a fifth layer702with the LGA layer710(a sixth layer) below the fifth layer702of the antenna structure700. The fifth layer702may correspond to the fifth layer602. As shown inFIG.7B, the fifth layer702may include RF traces that form transmission lines730and732, where end portions (shown by the dotted ovals) of the transmission lines730and732may form short circuit stubs that can interconnect the feeding ports720-1and720-2on the LGA layer710to other layers of the multi-layered PCB. In some aspects, the transmission line732may interconnect the feeding port720-2to feeding elements (e.g., the feeding elements550-1and550-2) that are electrically coupled the patch antenna element (disposed on the third layer of the multi-layered PCB). Similarly, the transmission line730may interconnect the feeding port720-1to feeding elements that are electrically coupled the patch antenna element.

In some aspects, each of the antenna structures300,400,500, and700discussed herein may have a small footprint (e.g., the side dimension316,416, and/or516) between about 0.25 λ0and about 0.3 λ0and may support a wide operating bandwidth, for example, with a fractional bandwidth up to about 25 %. The small footprint may enable the antenna structures300,400, and/or500to be arranged in an antenna array (e.g., the arrangements100and/or200) with a small inter-element pitch (e.g., the pitch104and204), and thereby capable of providing a wide scan range (e.g., with a scan angle of ± 70 degrees in each of azimuth and elevation). The small footprint may also be in terms of the height of the antenna structures300,400,500, and700to allow for packaging into SMT components.

In some aspects, each of the antenna structures300,400,500, and700discussed herein may support dual linear polarization with symmetric polarization performance. Further, each of the antenna structures300,400,500, and700discussed herein may support dual bands (e.g., 5G dual bands where one band may have a center frequency of about 24 GHz and another band may have a center frequency of about at 29.5 GHz). Thus, the antenna structures discussed herein can advantageously enable an RF system to utilize the same antenna structures or elements for operations in each of the dual bands rather than utilizing separate antenna structures or elements for different bands, thereby lowering cost and/or size of the RF system.

In general, the disclosed antenna structures (e.g., the antenna structures300,400,500, and700) may include stacked folded magnetoelectric antenna element (e.g., the magnetoelectric antenna element301) and patch antenna element (e.g., the patch antenna element320) printed on a multi-layered PCB (e.g., the multi-layered PCB structure600), where the folded magnetoelectric antenna element can be folded at one or more outer extents (with 2X folding or 3X folding) and/or one or more inner extents. Each of the horizontal fold portions and vertical fold portions may have any suitable length. In some use case scenarios, the folded magnetoelectric antenna element can be folded at one or more outer extents, but not at the inner extents. In other use case scenarios, the folded magnetoelectric antenna element can be folded at one or more inner extents, but not at the outer extents. In yet other use case scenarios, the folded magnetoelectric antenna element can be folded at one or more outer extents and at one or more inner extents. Further, the disclosed antenna structures suitable for use with single polarization excitation or dual polarization excitation and can be used with probe excitation or slot excitation.

Example Antenna Apparatus

FIG.8is a schematic diagram of an exemplary antenna apparatus800, e.g., a phased array system/apparatus, in which compact, wideband antenna elements are utilized to provide a wide scan range, according to some embodiments of the present disclosure. As shown inFIG.8, the antenna apparatus800may include an antenna array810, a beamformer array820, a UDC circuit840, and a controller870.

In general, the antenna array810may include a plurality of antenna elements812(only one of which is labeled with a reference numeral inFIG.8in order to not clutter the drawing), housed in (e.g., in or over) a substrate814, where the substrate814may be, e.g., a PCB or any other support structure. In various embodiments, the antenna elements812may be radiating elements or passive elements. For example, the antenna elements812may include dipoles, open-ended waveguides, slotted waveguides, microstrip antennas, and the like. In some embodiments, the antenna elements812may include any suitable elements configured to wirelessly transmit and/or receive RF signals. The antenna array810may be a phased array antenna and, therefore, will be referred to as such in the following. In some embodiments, the phased array antenna810may be a printed phased array antenna. In some embodiments, the antenna array810may be similar to the antenna array arrangements100or200.

At least some of the antenna elements812may be implemented using a combination of folded magnetoelectric antenna element (e.g., the folded magnetoelectric antenna element301) and patch antenna element (e.g., the patch antenna element320) formed or printed on a multi-layered PCB (e.g., the multi-layered PCB structure600) as discussed herein, and configured to have a wide operating bandwidth while extending the scan range of the phased array antenna810(e.g., with an azimuth scan angle and an elevation scan angle each up to about 70 degrees). Further details shown inFIG.8, such as the particular arrangement of the beamformer array820, of the UDC circuit840, and the relation between the beamformer array820and the UDC circuit840may be different in different embodiments, with the description ofFIG.8providing only some examples of how these components may be used together with the phased array antenna810including antenna elements812configured, for example, using the antenna structures300,400,500, and/or700. Furthermore, although some embodiments shown in the present drawings illustrate a certain number of components (e.g., a certain number of antenna elements812, beamformers, and/or UDC circuits), it is appreciated that these embodiments may be implemented with any number of these components in accordance with the descriptions provided herein. Furthermore, although the disclosure may discuss certain embodiments with reference to certain types of components of an antenna apparatus (e.g., referring to a substrate that houses antenna element as a PCB although in general it may be any suitable support structure), it is understood that the embodiments disclosed herein may be implemented with different types of components.

The beamformer array820may include a plurality of, beamformers822(only one of which is labeled with a reference numeral inFIG.8in order to not clutter the drawing). The beamformers822may be seen as transceivers (e.g., devices which may transmit and/or receive signals, in this case - RF signals) that feed to antenna elements812. In some embodiments, a single beamformer822may be associated with (i.e., exchange signals with, e.g., feed signals to) one of the antenna elements812(e.g., in a one-to-one correspondence). In other embodiments, multiple beamformers822may be associated with a single antenna element812. Yet in other embodiments, a single beamformer822may be associated with a plurality of antenna elements812. In some embodiments, when a given antenna element812is implemented with the antenna structure300,400,500, or700as discussed herein (e.g., with stacked folded magnetoelectric antenna element and patch antenna element printed on a multi-layered PCB), a dual polarized beamformer822may be configured to support signals for dual polarization. In general, one or more beamformers822may be connected to each antenna element812to support beamforming for signals with dual polarization.

In some embodiments, each of the beamformers822may include a switch824to switch the path from the corresponding antenna element812to the receiver or the transmitter path. Although not specifically shown inFIG.8, in some embodiments, each of the beamformers822may also include another switch to switch the path from a signal processor (also not shown) to the receiver or the transmitter path. As shown inFIG.8, in some embodiments, the transmit path (TX path) of each of the beamformers822may include a phase shifter826and a variable (e.g., programmable) gain amplifier828, while the receive path (RX path) may include a phase shifter830and a variable (e.g., programmable) gain amplifier832. The phase shifter826may be configured to adjust the phase of the RF signal to be transmitted (TX signal) by the antenna element812and the variable gain amplifier828may be configured to adjust the amplitude of the TX signal to be transmitted by the antenna element812. Similarly, the phase shifter830and the variable gain amplifier832may be configured to adjust the RF signal received (RX signal) by the antenna element812before providing the RX signal to further circuitry, e.g., to the UDC circuit840, to the signal processor (not shown), etc. The beamformers822may be considered to be “in the RF path” of the antenna apparatus800because the signals traversing the beamformers822are RF signals (i.e., TX signals which may traverse the beamformers822are RF signals upconverted by the UDC circuit840from lower frequency signals, e.g., from intermediate frequency (IF) signals or from baseband signals, while RX signals which may traverse the beamformers822are RF signals which have not yet been downconverted by the UDC circuit840to lower frequency signals, e.g., to IF signals or to baseband signals).

Although a switch is shown inFIG.8to switch from the transmitter path to the receive path (i.e., the switch824), in other embodiments of the beamformer822, other components can be used, such as a duplexer. Furthermore, althoughFIG.8illustrates an embodiment where the beamformers822include the phase shifters826,830(which may also be referred to as “phase adjusters”) and the variable gain amplifiers828,832, in other embodiments, any of the beamformers822may include other components to adjust the magnitude and/or the phase of the TX and/or RX signals. In some embodiments, one or more of the beamformers822may not include the phase shifter826and/or the phase shifter830because the desired phase adjustment may, alternatively, be performed using a phase shift module in the local oscillator (LO) path. In other embodiments, phase adjustment performed in the LO path may be combined with phase adjustment performed in the RF path using the phase shifters of the beamformers822.

Turning to the details of the UDC, in general, the UDC circuit840may include an upconverter and/or downconverter circuitry, i.e., in various embodiments, the UDC circuit840may include 8) an upconverter circuit but no downconverter circuit, 2) a downconverter circuit but no upconverter circuit, or 3) both an upconverter circuit and a downconverter circuit. As shown inFIG.8, in some embodiments, the downconverter circuit of the UDC circuit840may include an amplifier842and a mixer844, while the upconverter circuit of the UDC circuit840may include an amplifier846and a mixer848. In some embodiments, the UDC circuit840may further include a phase shift module850.

In various embodiments, the term “UDC circuit” may be used to include frequency conversion circuitry (e.g., a frequency mixer configured to perform upconversion to RF signals for wireless transmission, a frequency mixer configured to perform downconversion of received RF signals, or both), as well as any other components that may be included in a broader meaning of this term, such as filters, analog-to-digital converters (ADCs), digital-to-analog converters (DACs), transformers, and other circuit elements typically used in association with frequency mixers. In all of these variations, the term “UDC circuit” covers implementations where the UDC circuit840only includes circuit elements related to the TX path (e.g., only an upconversion mixer but not a downconversion mixer; in such implementations the UDC circuit may be used as/in an RF transmitter for generating RF signals for transmission), implementations where the UDC circuit840only includes circuit elements related to the RX path (e.g., only an downconversion mixer but not an upconversion mixer; in such implementations the UDC circuit840may be used as/in an RF receiver to downconvert received RF signals, e.g., the UDC circuit840may enable an antenna element of the phased array antenna810to act, or be used, as a receiver), as well as implementations where the UDC circuit840includes, both, circuit elements of the TX path and circuit elements of the RX path (e.g., both the upconversion mixer and the downconversion mixer; in such implementations the UDC circuit840may be used as/in an RF transceiver, e.g., the UDC circuit840may enable an antenna element of the phased array antenna810to act, or be used, as a transceiver).

Although a single UDC circuit840is illustrated inFIG.8, multiple UDC circuits840may be included in the antenna apparatus800to provide upconverted RF signals to and/or receive RF signals to be downconverted from any one of the beamformers822. Each UDC circuit840may be associated with a plurality of beamformers822of the beamformer array820, e.g., using a splitter/combiner. This is schematically illustrated inFIG.8with dashed lines and dotted lines within the splitter/combiner connecting various elements of the beamformer array820and the UDC circuit840. Namely,FIG.8illustrates that the dashed lines connect the downconverter circuit of the UDC circuit840(namely, the amplifier842) to the RX paths of two different beamformers822, and that the dotted lines connect the upconverter circuit of the UDC circuit840(namely, the amplifier846) to the TX paths of two different beamformers822. For example, there may be 96 beamformers822in the beamformer array820, associated with 96 antenna elements812of the phased array antenna810.

In some embodiments, the mixer844in the downconverter path (i.e., RX path) of the UDC circuit840may have at least two inputs and one output. One of the inputs of the mixer844may include an input from the amplifier842, which may, e.g., be a low-noise amplifier (LNA). The second input of the mixer844may include an input indicative of the LO signal860. In some embodiments, phase shifting may be implemented in the LO path (additionally or alternatively to the phase shifting in the RF path), in which case the LO signal860may be provided, first, to a phase shift module850, and then a phase-shifted LO signal860is provided as the second input to the mixer844. In the embodiments where phase shifting in the LO path is not implemented, the phase shift module850may be absent and the second input of the mixer844may be configured to receive the LO signal860. The one output of the mixer844is an output to provide the downconverted signal856, which may, e.g., be an IF signal856. The mixer844may be configured to receive an RF RX signal from the RX path of one of the beamformers822, after it has been amplified by the amplifier842, at its first input and receive either a signal from the phase shift module850or the LO signal860itself at its second input, and mix these two signals to downconvert the RF RX signal to an lower frequency, producing the downconverted RX signal856, e.g., the RX signal at the IF. Thus, the mixer844in the downconverter path of the UDC circuit840may be referred to as a “downconverting mixer.”

In some embodiments, the mixer848in the upconverter path (i.e., TX path) of the UDC circuit840may have [at least] two inputs and one output. The first input of the mixer848may be an input for receiving a TX signal858of a lower frequency, e.g., the TX signal at IF. The second input of the mixer848may include an input indicative of the LO signal860. In the embodiments where phase shifting is implemented in the LO path (either additionally or alternatively to the phase shifting in the RF path), the LO signal860may be provided, first, to a phase shift module850, and then a phase-shifted LO signal860is provided as the second input to the mixer848. In the embodiments where phase shifting in the LO path is not implemented, the phase shift module850may be absent and the second input of the mixer848may be configured to receive the LO signal860. The one output of the mixer848is an output to the amplifier846, which may, e.g., be a power amplifier (PA). The mixer848may be configured to receive an IF TX signal858(i.e., the lower frequency, e.g. IF, signal to be transmitted) at its first input and receive either a signal from the phase shift module850or the LO signal860itself at its second input, and mix these two signals to upconvert the IF TX signal to the desired RF frequency, producing the upconverted RF TX signal to be provided, after it has been amplified by the amplifier846, to the TX path of one of the beamformers822. Thus, the mixer848in the upconverter path of the UDC circuit840may be referred to as a “upconverting mixer.”

In some embodiments, the amplifier828may be a PA and/or the amplifier832may be an LNA.

As is known in communications and electronic engineering, an IF is a frequency to which a carrier wave is shifted as an intermediate step in transmission or reception. The IF signal may be created by mixing the carrier signal with an LO signal in a process called heterodyning, resulting in a signal at the difference or beat frequency. Conversion to IF may be useful for several reasons. One reason is that, when several stages of filters are used, they can all be set to a fixed frequency, which makes them easier to build and to tune. Another reason is that lower frequency transistors generally have higher gains so fewer stages may be required. Yet another reason is to improve frequency selectivity because it may be easier to make sharply selective filters at lower fixed frequencies. It should also be noted that, while some descriptions provided herein refer to signals856and858as IF signals, these descriptions are equally applicable to embodiments where signals856and858are baseband signals. In such embodiments, frequency mixing of the mixers844and848may be a zero-IF mixing (also referred to as a “zero-IF conversion”) in which the LO signal860used to perform the mixing may have a center frequency in the band of RF RX/TX frequencies.

Although not specifically shown inFIG.8, in further embodiments, the UDC circuit840may further include a balancer, e.g., in each of the TX and RX paths, configured to mitigate imbalances in the in-phase and quadrature (IQ) signals due to mismatching. Furthermore, although also not specifically shown inFIG.8, in other embodiments, the antenna apparatus800may include further instances of a combination of the phased array antenna810, the beamformer array820, and the UDC circuit840as described herein.

The controller870may include any suitable device, configured to control operation of various parts of the antenna apparatus800. For example, in some embodiments, the controller870may control the amount and the timing of phase shifting implemented in the antenna apparatus800. In another example, in some embodiments, the controller870may control various signals, as well as the timing of those signals, provided to the antenna elements812implemented using the antenna structures300,400,500, and/or700in the antenna array810to provide a wide scan range.

The antenna apparatus800can steer an electromagnetic radiation pattern of the phased array antenna810in a particular direction, thereby enabling the phased array antenna810to generate a main beam in that direction and side lobes in other directions. The main beam of the radiation pattern is generated based on constructive inference of the transmitted RF signals based on the transmitted signals’ phases. The side lobe levels may be determined by the amplitudes of the RF signals transmitted by the antenna elements. The antenna apparatus800can generate desired antenna patterns by providing phase shifter settings for the antenna elements812, e.g., using the phase shifters of the beamformers822and/or the phase shift module850.

EXAMPLES

Example 1 includes an antenna structure including a multi-layered printed circuit board (PCB); a folded magnetoelectric antenna element including a first portion disposed on a first layer of the multi-layered PCB and a first fold portion contiguous to the first portion and extending to at least a second layer of the multi-layered PCB; and a patch antenna element disposed on a third layer of the multi-layered PCB, where the first, second, and third layers are separate layers of the multi-layered PCB.

Example 2 includes the antenna structure of Example 1, where the folded magnetoelectric antenna element further includes a second fold portion contiguous to the first fold portion and disposed on the second layer of the multi-layered PCB.

Example 3 includes the antenna structure of any of Examples 1-2, where the second layer is between the first layer and the third layer, and where the first fold portion of the folded magnetoelectric antenna element further extends to the third layer of the multi-layered PCB.

Example 4 includes the antenna structure of any of Examples 1-3, where the folded magnetoelectric antenna element further includes a third fold portion contiguous to the first fold portion and disposed on the third layer of the multi-layered PCB.

Example 5 includes the antenna structure of any of Examples 1-4, where the first fold portion of the folded magnetoelectric antenna element extends along a side of the antenna structure.

Example 6 includes the antenna structure of any of Examples 1-5, where the folded magnetoelectric antenna element includes a plurality of folded patches spaced apart from each other, and where the first portion and the first fold portion correspond to a first folded patch of the plurality of folded patch.

Example 7 includes the antenna structure of any of Examples 1-6, where an outer edge of the first folded patch is folded to form the first fold portion.

Example 8 includes the antenna structure of any of Examples 1-6, where an inner edge of the first folded patch is folded to form the first fold portion.

Example 9 includes the antenna structure of any of Examples 1-6, where a second folded patch of the plurality of folded patches includes a second portion disposed on the first layer of the multi-layered PCB and a second fold portion contiguous to the second portion and extending to at least the second layer of the multi-layered PCB, and where an inner edge of the second folded patch is folded to form the second fold portion.

Example 10 includes the antenna structure of any of Examples 1-9, where the folded magnetoelectric antenna element is connected to a ground layer of the multi-layered PCB by at least two staggered vias.

Example 11 includes the antenna structure of any of Examples 1-10, where the at least two staggered vias that connect the folded magnetoelectric antenna element to the ground layer includes a first via extending from the first layer to the second layer; and a second via extending from the second layer to the ground layer.

Example 12 includes the antenna structure of any of Examples 1-11, where the patch antenna element includes a squared shape patch antenna, a rectangular shaped patch antenna, or a microstrip antenna.

Example 13 includes the antenna structure of any of Examples 1-12, and further include a first feeding port electrically coupled to the patch antenna element, where the first feeding port is associated with a first polarization; and a second feeding port electrically coupled to the patch antenna element, and where the second feeding port is associated with a second polarization different from the first polarization.

Example 14 includes a multi-layered printed circuit board (PCB) antenna device, including a plurality of PCB layers; a folded magnetoelectric antenna element including a plurality of patches disposed on a first PCB layer of the plurality of PCB layers and spaced apart from each other, where one or more edges of a first patch of the plurality of patches are folded and extend vertically towards a second PCB layer of the plurality of PCB layers, where the second PCB layer is vertically below the first PCB layer; a patch antenna element disposed on a third PCB layer of the plurality of PCB layers, where the third PCB layer is vertically below the second PCB layer; a first feeding port electrically coupled to the patch antenna element, where the first feeding port is associated with a first polarization; and a second feeding port electrically coupled to the patch antenna element, where the second feeding port is associated with a second polarization different from the first polarization.

Example 15 includes the multi-layered PCB antenna device of Example 14, where the one or more edges of the first patch that are folded further extends to the third PCB layer.

Example 16 includes the multi-layered PCB antenna device of any of Examples 14-15, where the one or more edges of the first patch that are folded includes at least one of an outer edge of the first patch or an inner edge of the first patch.

Example 17 includes the multi-layered PCB antenna device of any of Examples 14-16, where the one or more edges of the first patch that are folded includes the inner edge of the first patch, and where an inner edge of a second patch of the plurality of patches is folded and extends towards the second PCB layer.

Example 18 includes the multi-layered PCB antenna device of any of Examples 14-17, where a side dimension of the folded magnetoelectric antenna element is between 0.25 and 0.3 of a wavelength.

Example 19 includes the multi-layered PCB antenna device of any of Examples 14-18, where each of the plurality of patches of the folded magnetoelectric antenna element is electrically coupled to a ground layer of the plurality of PCB layers via two or more staggered PCB vias.

Example 20 includes the multi-layered PCB antenna device of any of Examples 14-19, where the plurality of PCB layers are spaced apart from each other by dielectric material having a dielectric constant between 3 and 4.

Example 21 includes the multi-layered PCB antenna device of any of Examples 14-20, where the third PCB layer and a ground layer of the plurality of PCB layers are spaced apart by a PCB core having height between 0.05 and 0.2 of a free-space wavelength.

Example 22 includes the multi-layered PCB antenna device of any of Examples 14-21, where the first, second, and third PCB layers are spaced apart from a fourth, fifth, and sixth PCB layers of the plurality of PCB layers by a PCB core.

Example 23 includes an antenna array apparatus including a plurality of antenna elements, where a first antenna element of the plurality of antenna elements includes a plurality of printed circuity board (PCB) layers; a folded magnetoelectric antenna element including a plurality of patches disposed on a first PCB layer of the plurality of PCB layers and spaced apart from each other, where one or more edges of a first patch of the plurality of patches are folded and extend vertically towards a second PCB layer of the plurality of PCB layers, where the second PCB layer is vertically below the first PCB layer; and a patch antenna element disposed on a third PCB layer of the plurality of PCB layers, where the third PCB layer is vertically below the second PCB layer.

Example 24 includes the antenna array apparatus of Example 23, where the one or more edges of the first patch that are folded further extends to the third PCB layer.

Example 25 includes the antenna array apparatus of any of Examples 23-24, where the one or more edges of the first patch that are folded includes at least one of an outer edge of the first patch or an inner edge of the first patch.

Example 26 includes the antenna array apparatus of any of Examples 23-25, where the one or more edges of the first patch that are folded includes the inner edge of the first patch, and where an inner edge of a second patch of the plurality of patches is folded and extends towards the second PCB layer.

Example 27 includes the antenna array apparatus of any of Examples 23-26, where the first antenna element is housed in a surface mount technology (SMT) package.

Example 28 includes the antenna array apparatus of any of Examples 23-27, where the plurality of antenna elements provides a scan range including at least one of an azimuth scan angle up to 70 degrees or an elevation scan angle up to 70 degrees.

Variations and Implementations

While embodiments of the present disclosure were described above with references to exemplary implementations as shown inFIGS.1-2,3A-3B,4A-4B,5A-5F,6,7A-7B, and8, a person skilled in the art will realize that the various teachings described above are applicable to a large variety of other implementations._For example, descriptions provided herein are applicable not only to 5G systems, which provide one example of wireless communication systems, but also to other wireless communication systems such as, but not limited to, Wi-Fi technology or Bluetooth technology. In yet another example, descriptions provided herein are applicable not only to wireless communication systems, but also to any other systems where antenna arrays may be used, such as radar systems.

In certain contexts, the features discussed herein can be applicable to automotive systems, medical systems, scientific instrumentation, wireless and wired communications, radio, radar, and digital-processing-based systems.

In the discussions of the embodiments above, components of a system, such as phase shifters, vias, and/or other components can readily be replaced, substituted, or otherwise modified in order to accommodate particular circuitry needs. Moreover, it should be noted that the use of complementary electronic devices, hardware, software, etc., offer an equally viable option for implementing the teachings of the present disclosure related to providing compact, wideband antenna structures suitable for use in a wide scan angle antenna array as described herein.

It is also imperative to note that all of the specifications, dimensions, and relationships outlined herein (e.g., the number of components shown in the antenna arrangements ofFIGS.1-2, the antenna structures ofFIGS.3A-3B,4A-4B,5A-5F,6,7A-7B, and the apparatus fFIG.8) have only been offered for purposes of example and teaching only. Such information may be varied considerably without departing from the spirit of the present disclosure. It should be appreciated that the system can be consolidated in any suitable manner. Along similar design alternatives, any of the illustrated circuits, components, modules, and elements of the present drawings may be combined in various possible configurations, all of which are clearly within the broad scope of this specification. In the foregoing description, example embodiments have been described with reference to particular component arrangements. Various modifications and changes may be made to such embodiments without departing from the scope of the present disclosure. The description and drawings are, accordingly, to be regarded in an illustrative rather than in a restrictive sense.

Note that in this Specification, references to various features (e.g., elements, structures, modules, components, steps, operations, characteristics, etc.) included in “one embodiment”, “example embodiment”, “an embodiment”, “another embodiment”, “some embodiments”, “various embodiments”, “other embodiments”, “alternative embodiment”, and the like are intended to mean that any such features are included in one or more embodiments of the present disclosure, but may or may not necessarily be combined in the same embodiments. Also, as used herein, including in the claims, “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates an inclusive list such that, for example, a list of [at least one of A, B, or C] means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

Various aspects of the illustrative embodiments are described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. For example, the term “connected” means a direct electrical connection between the things that are connected, without any intermediary devices/components, while the term “coupled” means either a direct electrical connection between the things that are connected, or an indirect connection through one or more passive or active intermediary devices/components. In another example, the term “circuit” means one or more passive and/or active components that are arranged to cooperate with one another to provide a desired function. Also, as used herein, the terms “substantially,” “approximately,” “about,” etc., may be used to generally refer to being within +/- 20% of a target value, e.g., within +/- 10% of a target value, based on the context of a particular value as described herein or as known in the art.

Numerous other changes, substitutions, variations, alterations, and modifications may be ascertained to one skilled in the art and it is intended that the present disclosure encompass all such changes, substitutions, variations, alterations, and modifications as falling within the scope of the examples and appended claims. Note that all optional features of the apparatus described above may also be implemented with respect to the method or process described herein and specifics in the examples may be used anywhere in one or more embodiments.