Patent Description:
As the <NUM> (5th-Generation) communication era begins, millimeter wave transmission has become an important choice for global operators. During the millimeter wave transmission, a millimeter-wave antenna plays an important role as a terminal transceiver. As a frequency of a communication signal increases, signal loss on a transmission line also increases sharply, to affect communication quality. Antenna in Package (AiP), can better resolve the problem of a large signal loss on the transmission line. In the AiP, an antenna (Antenna) is integrated with a chip and packed in a package structure. This reduces a transmission loss between the antenna and the chip, and effectively improves performance of the package structure.

<CIT> describes an integrated circuit package comprising an integrated circuit die and an antenna structure coupled to the integrated circuit die and comprising a stacked arrangement of metal and dielectric layers, wherein a first metal layer includes a planar antenna and at least one further metal layer comprises an artificial dielectric layer.

<NPL>, describes optimization of metamaterial based subwavelength cavities for ultracompact directive antennas, and specifically presents a design for a microstrip antenna operating near <NUM> with a cavity thickness of <NUM>.

<NPL>, describes a high-gain low-profile sub-wavelength substrate-integrated Fabry-Perot (FP) cavity antenna with artificial magnetic conductor (AMC) sheets, and specifically presents a design for a Fabry-Perot cavity antenna operating at <NUM> with a cavity thickness of <NUM>.

<NPL>, describes a structure evolved from a Fabry-Perot (FP) cavity with a patch antenna acting as the feed and four metallic walls on the lateral sides, and specifically presents a highly directive metamaterial-based cavity antenna for a <NUM> application.

A terminal device (especially a mobile phone device) has a complex internal structure and has a relatively strict requirement on a thickness of a millimeter-wave antenna in package. <FIG> is a schematic structural diagram of a millimeter-wave antenna in package <NUM>, including an upper substrate <NUM> and a lower substrate <NUM> that are disposed oppositely, an upper radiation patch <NUM> (namely, an antenna) disposed on the lower surface of the upper substrate <NUM>, and a lower radiation patch <NUM> disposed on the upper surface of the lower substrate <NUM>. The upper substrate <NUM> and the lower substrate <NUM> are electrically connected by using solder balls <NUM>. The upper radiation patch <NUM> and the lower radiation patch <NUM> are coupled and form dual resonance, to extend a bandwidth of the antenna. To meet a requirement of a relatively high bandwidth of the antenna, a spacing between the lower radiation patch <NUM> and the upper radiation patch <NUM> is relatively large. Consequently, it is difficult to meet a requirement of a terminal device (especially a mobile phone device) for a low profile of a millimeter-wave antenna in package. As a result, the terminal device has a relatively large size and becomes difficult to carry.

Embodiments of this application provide an antenna in package, to resolve a problem that an antenna in a terminal device, especially a mobile phone device, has a relatively high profile and occupies relatively large space. Preferred embodiments are described by the dependent claims.

According to a first aspect, an embodiment of this application provides an antenna in package, including a substrate, and a radio frequency processing chip disposed on a side of the substrate and electrically connected to the substrate. The substrate includes N radiation patches, N overlay arrays, and a feed path that are disposed in the substrate. The N overlay arrays are disposed on one side of the N radiation patches to respectively form N resonant cavities, and the one side faces away from the radio frequency processing chip. The radio frequency processing chip feeds power to the N radiation patches through the feed path, and resonates the N overlay arrays. A frequency of the overlay array when a reflection phase is <NUM>° is within an operating band of the antenna in package. In other words, the overlay array has a zero reflection phase region within the operating band.

Because the frequency of the overlay array when the reflection phase is <NUM>° is within the operating band, the overlay array has a lower reflection phase compared with an overlay array in the conventional technology, so that the radiation patch and the overlay array can still generate resonance after the resonant cavity of the antenna in package decreases in height. Therefore, reduction in the height of the resonant cavity by using the overlay array reduces the height of the entire antenna in package. This miniaturizes a profile of the antenna in package.

The overlay array is a metamaterial. The metamaterial is used as a material of the overlay array, and therefore, because having a special periodic structure, the metamaterial can provide, within the operating band, a reflection phase close to <NUM>° for an incident electromagnetic wave.

The antenna in package further includes a dielectric layer configured to fill the resonant cavity. The dielectric layer is used to fill the resonant cavity, so that the overlay array obtains physical support, and a structure of the antenna in package is more stable.

The antenna in package further includes an antenna reference ground layer. The antenna reference ground layer is disposed on a side, of the radiation patch, facing the radio frequency processing chip, and is configured to provide a reference ground for the radiation patch. The antenna reference ground layer provides a reference ground for the radiation patch, so that the radiation patch can operate normally.

The antenna in package further includes a signal reference ground layer. The signal reference ground layer is disposed on a side, of the antenna reference ground layer, facing the radio frequency processing chip, and is configured to provide a reference ground for another signal such as a digital signal, an intermediate frequency signal, or a power supply signal. The signal reference ground layer provides a reference ground for another signal such as a digital signal, an intermediate frequency signal, or a power supply signal, so that the signal can operate normally.

The antenna in package further includes a signal layer. The signal layer is disposed on a side, of the signal reference ground layer, facing the radio frequency processing chip, and includes a routing of another signal such as a digital signal, an intermediate frequency signal, or a power supply signal. The signal layer is disposed in the antenna in package, so that the antenna in package can conduct and process another signal such as a digital signal, an intermediate frequency signal, or a power supply signal.

The overlay array includes a plurality of overlay patches arranged in an array, and a size of each overlay patch is less than a wavelength corresponding to any frequency within the operating band. Because the size of the overlay patch is less than the wavelength, the overlay array can change a phase of the incident electromagnetic wave.

In a possible design, the plurality of overlay patches are arranged in a Q × Q array, each overlay patch has a same size and shape, spacings between the overlay patches are the same, and Q is greater than <NUM>. Even arrangement of the plurality of overlay patches simplifies a manufacturing process of the overlay patches.

In a possible design, a first frequency and a second frequency decrease as an area of each overlay patch increases. The first frequency is a corresponding frequency of the overlay array when the reflection phase is equal to -<NUM>°. The second frequency is a corresponding frequency of the overlay array when the reflection phase is equal to <NUM>°. A reflection phase characteristic of the overlay array is adjusted by adjusting the area of the overlay patch, so that a zero reflection characteristic region provided by the overlay array can better cover the operating band.

In a possible design, the first frequency and the second frequency decrease as spacings between the overlay patches decrease. A reflection phase characteristic of the overlay array is adjusted by adjusting the spacings between the overlay patches, so that a zero reflection characteristic region provided by the overlay array can better cover the operating band.

In a possible design, a difference between the second frequency and the first frequency increases as a distance between the overlay array and the radiation patch (or a height of the formed resonant cavity) increases. The reflection phase characteristic of the overlay array is adjusted by adjusting the distance (or the height of the formed resonant cavity), so that the zero reflection characteristic region provided by the overlay array can better cover the operating band.

In a possible design, a resonance frequency generated by the overlay array decreases as an area of each overlay patch increases. The resonance frequency generated by the overlay array is adjusted by adjusting the area of the overlay patch, so as to facilitate adjustment in locations of two resonance points generated by the overlay array and the radiation patch, and obtain a better broadband characteristic within the operating band.

In a possible design, each overlay patch is a regular hexagon. Setting the overlay patch to a regular hexagon helps a feed path polarize a radiation patch corresponding to the feed path.

In a possible design, each overlay patch is a square. Setting the overlay patch to a square helps a feed path polarize a radiation patch corresponding to the feed path, and this is simpler in process and easy to implement.

In a possible design, the one or more overlay arrays are a plurality of overlay arrays arranged in an array. The plurality of overlay arrays arranged in an array may improve antenna performance, increase an antenna gain, and enhance an antenna beam sweeping capability.

In a possible design, the plurality of overlay arrays are arranged in an M × M array, spacings between the overlay arrays are the same, and M is greater than <NUM>. Even arrangement of the plurality of overlay arrays simplifies a manufacturing process of the plurality of overlay arrays.

In a possible design, a center of one radiation patch and a center of one overlay array in the resonant assembly are aligned in a direction perpendicular to the substrate. Aligning the center of the radiation patch with the center of the overlay array enables the overlay array to generate better resonance.

In a possible design, the overlay array is a graphene array. Using graphene as a material for forming the overlay array may provide a reflection phase ranging from -<NUM>° to <NUM>°.

In a possible design, the overlay array is a copper patch array. Using copper as a material for forming the overlay array may further reduce costs of manufacturing the antenna in package.

According to a second aspect, an embodiment of this application provides a radio frequency signal processing apparatus, including a printed circuit board, and an antenna in package that is disposed on a surface of the printed circuit board and that is electrically connected to the printed circuit board, where the antenna in package is the antenna in package in the first aspect and the possible designs of the first aspect.

Because the frequency of the overlay array when the reflection phase is <NUM>° is within the operating band, the overlay array has a lower reflection phase compared with an overlay array in the conventional technology, so that the radiation patch and the overlay array can still generate resonance after the resonant cavity of the antenna in package decreases in height. Therefore, reduction in the height of the resonant cavity by using the overlay array reduces the height of the entire antenna in package. This miniaturizes the profile of the antenna in package.

To describe the technical solutions in the embodiments of this application or in the conventional technology more clearly, the following briefly describes the accompanying drawings for describing the embodiments or the conventional technology.

Antenna in package <NUM>; substrate <NUM>; antenna reference ground layer <NUM>; signal reference ground layer <NUM>; signal layer <NUM>; feed path <NUM>; radio frequency signal routing <NUM>; vertical polarization feed post <NUM>; horizontal polarization feed post <NUM>; metalized via <NUM>; radiation patch <NUM>; overlay array <NUM>; overlay patch <NUM>; radio frequency processing chip <NUM>; solder ball <NUM>; and a dielectric layer <NUM>.

It is clearly that the described embodiments are merely some but not all of the embodiments of this application.

It should be noted that, in the embodiments of this application, "a plurality" refers to two or more, for example, may be two, three, or four. In addition, it should be understood that, in the descriptions of this application, terms such as "first" and "second" are merely used for distinguishing and description purposes, and cannot be understood as indicating or implying relative importance, or as indicating or implying a sequence. In addition, in the descriptions of this application, terms such as "upper" and "lower" are only used to distinguish relative orientations, and cannot be understood as a limitation on orientations. That A includes at least one of B or C means that A includes B, C, or B + C.

<FIG> is a schematic sectional view of an antenna in package <NUM> according to an embodiment not falling under the scope of the claims of this application. The antenna in package <NUM> may be configured to process and transmit an electromagnetic wave signal, for example, a millimeter wave signal. The antenna in package <NUM> includes a substrate <NUM> and a radio frequency processing chip <NUM> disposed on a lower surface side of the substrate <NUM>. The radio frequency processing chip <NUM> is electrically connected to the substrate <NUM>, for example, by using a plurality of solder balls <NUM>. The radio frequency processing chip <NUM> may be configured to perform frequency synthesis and power amplification on an electromagnetic wave signal. For example, the radio frequency processing chip <NUM> may include at least one of a power amplifier (AP), an antenna switch (Switch), a filter (Filter), a duplexer (Duplexer), or a low noise amplifier (LNA). The substrate <NUM> includes a feed path <NUM>, N radiation patches <NUM>, and N overlay arrays <NUM> that are disposed in the substrate <NUM> (N ≥ <NUM> and N is an integer). The overlay array <NUM> is disposed on an upper surface side of the radiation patch <NUM>, to be specific, a side, of the radiation patch <NUM>, facing away from the radio frequency processing chip <NUM>. The N overlay arrays <NUM> and the N radiation patches <NUM> corresponding to the N overlay arrays <NUM> form N resonant cavities. In the resonant cavity, a center of the overlay array <NUM> and a center of the radiation patch <NUM> are aligned in a vertical direction. A reflection phase of the overlay array <NUM> is greater than or equal to -<NUM>° and less than or equal to <NUM>° within an operating band of the antenna, and the reflection phase within the operating band may reach <NUM>°, to be specific, a reflection phase of at least one frequency within the operating band may reach <NUM>°. Ideally, the reflection phase of the overlay array <NUM> may be close to <NUM>° within the operating band. The radio frequency processing chip <NUM> feeds power to the radiation patch <NUM> through the feed path <NUM>, to excite radiant energy. In this application, the operating band is an operating band of the antenna in the antenna in package <NUM>, to be specific, a frequency of an electromagnetic wave transmitted or received by the antenna during normal operation, for example, from <NUM> to <NUM>. The antenna may include the radiation patch <NUM>, the overlay array <NUM>, and another signal layer such as a ground layer, an intermediate frequency signal layer, or a low frequency signal layer. The antenna in package <NUM> shown in <FIG> is described by using one radiation patch <NUM> and one overlay array <NUM> as an example. The antenna in package <NUM> according to the embodiments of this application may include at least N radiation patches <NUM> and N overlay arrays <NUM>.

A reflection phase (reflection phase) is a parameter for a reflection plane and is defined as a phase change of the reflection plane to an incident wave. For example, a perfect electric conductor (PEC) has a reflection phase of <NUM>°. When a phase of an incident wave is Φ, a phase of the reflected wave is Φ + <NUM>°. A perfect magnetic conductor (Perfect Magnetic Conductor, PMC) has a reflection phase of <NUM>°. When a phase of an incident wave is Φ, a phase of the reflected wave is also Φ.

The resonant cavity in the antenna in package <NUM> meets the following formula: <MAT>.

In this formula, f is a frequency of an electromagnetic wave received or transmitted by the antenna in package <NUM>, d is a height of the resonant cavity, to be specific, a distance between the radiation patch <NUM> and the overlay array <NUM> in a normal direction of the radio frequency processing chip <NUM>, c is a speed of light, and ΔΦ<NUM> is an absolute value of a reflection phase of the overlay array <NUM>, ΔΦ<NUM> is an absolute value of a reflection phase of the radiation patch <NUM>, and m is any integer. When the reflection phase ΔΦ<NUM> of the radiation patch <NUM> is <NUM>° and remains unchanged, the reflection phase ΔΦ<NUM> of the overlay array <NUM> within the operating band may change from <NUM>° in the conventional technology to less than <NUM>° within the operating band, and a reflection phase of at least one frequency within the operating band reaches <NUM>°. In formula (<NUM>), if m remains unchanged, ΔΦ<NUM> decreases and the height d of the resonant cavity decreases accordingly and simultaneously. Therefore, using the overlay array <NUM> whose reflection phase can reach <NUM>° within the operating band can reduce the height d of the resonant cavity. This reduces a profile of the antenna in package <NUM>, so that the antenna in package <NUM> can meet a requirement of a terminal device (especially a mobile phone) for a low-profile antenna in package.

For example, the reflection phase ΔΦ<NUM> of the overlay array <NUM> used in the conventional technology within the operating band is <NUM>°, and the reflection phase ΔΦ<NUM> of the radiation patch <NUM> is also <NUM>°. The foregoing parameters are substituted into formula (<NUM>) to obtain: <MAT>.

When m = <NUM>, a height d<NUM> of the resonant cavity may be a minimum positive value, to be specific, d<NUM> = c/(<NUM>f) = <NUM>/4λ. However, in the antenna in package <NUM> according to this embodiment of this application, the reflection phase ΔΦ<NUM> of the overlay array <NUM> within the operating band may be close to <NUM>° in an ideal case, and the foregoing data may be substituted into formula (<NUM>) to obtain: <MAT>.

When m = <NUM>, a height d<NUM> of the resonant cavity may be a minimum positive value, to be specific, d<NUM> = <NUM>/8λ. Therefore, the height d of the resonant cavity is reduced from <NUM>/4λ to <NUM>/8λ, reducing the profile of the antenna in package <NUM>.

<FIG> is a schematic sectional view of a more specific antenna in package <NUM>. The antenna in package <NUM> further includes an antenna reference ground layer <NUM>, a signal reference ground layer <NUM>, and a signal layer <NUM> that are disposed in the substrate <NUM>, and a dielectric layer <NUM> that is configured to fill the resonant cavity and disposed in the substrate <NUM>. The dielectric layer <NUM> is disposed between the radiation patch <NUM> and the overlay array patch <NUM>, to support the overlay array patch <NUM>, and fill the resonant cavity formed between the radiation patch <NUM> and the overlay array patch <NUM>. In an implementation, a material of the dielectric layer <NUM> may be the same as a material of the substrate <NUM>. In another implementation, the dielectric layer <NUM> may use a microwave dielectric material, for example, one of the following materials: BaO-TiO<NUM>, Al<NUM>O<NUM> perovskite ceramic, polytetrafluoroethylene, quartz, or beryllium oxide.

The antenna reference ground layer <NUM> is disposed below the radiation patch <NUM>, to be specific, a side, of the radiation patch <NUM>, facing the radio frequency processing chip <NUM>, and is configured to provide a reference ground of the radiation patch <NUM>. The signal reference ground layer <NUM> is disposed below the antenna reference ground layer <NUM>, to be specific, a side, of the antenna reference ground layer <NUM>, facing the radio frequency processing chip <NUM>, and is configured to provide a reference ground for a digital signal, an intermediate frequency signal, a power supply signal, and another signal. The signal layer <NUM> is disposed below the signal reference ground layer <NUM>, to be specific, a side, of the signal reference ground layer <NUM>, facing the radio frequency processing chip <NUM>. The signal layer <NUM> includes a routing of at least one of a digital signal, an intermediate frequency signal, and a power supply signal. It should be noted that the substrate <NUM> may include one or more antenna reference ground layers <NUM>, one or more signal reference ground layers <NUM>, or one or more signal layers <NUM>. A specific quantity and an arrangement sequence of the antenna reference ground layers <NUM>, the signal reference ground layers <NUM>, and the signal layers <NUM> are not limited in this application.

In this embodiment of this application, a dual-polarization antenna is used as an example to describe an operating principle of the antenna in package <NUM>. Alternatively, the antenna in package <NUM> may be a single-polarization antenna. It should be noted that a polarization manner of the antenna in package <NUM> is not limited in this application. The feed path <NUM> in the antenna in package <NUM> includes a radio frequency signal routing <NUM> and a feed post. The radio frequency signal routing <NUM> provides an appropriate matching circuit for the radiation patch <NUM>, so as to extend an antenna bandwidth. In addition, a length of the radio frequency routing is properly controlled, so that a phase of each radio frequency channel from the radio frequency processing chip <NUM> to the radiation patch <NUM> reaches a preset value. The feed post includes a vertical polarization feed post <NUM> and a horizontal polarization feed post <NUM>, so as to excite radiant energy of the radiation patch <NUM> in a horizontal polarization direction and in a vertical polarization direction. This achieves a dual polarization purpose. The antenna in package <NUM> further includes one or more metalized vias <NUM>. The vertical polarization feed post <NUM> and the horizontal polarization feed post <NUM> are disposed in the metalized vias <NUM>. The vertical polarization feed post <NUM> and the horizontal polarization feed post <NUM> excite the radiation patch <NUM> and generate a first resonance frequency. The first resonance frequency excites the overlay radiation array <NUM>, and enables the overlay radiation array <NUM> to generate a second resonance frequency. A bandwidth of the antenna in package <NUM> during operation is determined by using the first resonance frequency and the second resonance frequency. Specifically, a frequency of an electromagnetic wave transmitted or received by the antenna in package <NUM> is between the first resonance frequency and the second resonance frequency (including the first resonance frequency and the second resonance frequency).

A material of the overlay array <NUM> is a metamaterial (Metamaterial), a reflection phase of the metamaterial within an operating band is greater than or equal to -<NUM>° and less than or equal to <NUM>°, and a frequency of the metamaterial when the reflection phase is <NUM>° is within the operating band. The metamaterial is an artificial material with a periodic arrangement structure, and by using a special and precise geometrical structure and size, realizes characteristics that ordinary materials do not have. A size of a microstructure in the metamaterial is less than a wavelength of an electromagnetic wave that the metamaterial acts on, to exert an influence on the electromagnetic wave, for example, providing a reflection phase close to <NUM>° for the electromagnetic wave. The metamaterial forming the overlay array <NUM> may be graphene (Graphene), or may be metal, for example, copper or silver. For example, in an implementation, the overlay array <NUM> is a copper patch array.

The overlay patch array <NUM> includes a plurality of overlay patches arranged in an array. The array arrangement may be a square array arrangement, for example, a Q × Q array arrangement (Q > <NUM>), or may be a rectangular array arrangement, for example, a P × Q array arrangement (P ≠ Q and P > <NUM>), or may be a single-column array arrangement, for example, a Q × <NUM> array arrangement (Q > <NUM>), or may be a trapezoidal array arrangement, or may be an array arrangement of another shape.

<FIG> is a top view of the overlay array <NUM>, and a plurality of overlay patches <NUM> arranged in a Q × Q array are used as an example for description. The overlay array <NUM> includes a plurality of overlay patches <NUM> arranged in a Q × Q array. In <FIG>, Q = <NUM>, and each overlay patch <NUM> is a square. However, this application sets no limitation on Q or a specific shape of the overlay patch <NUM>, provided that Q > <NUM>. A size of each overlay patch <NUM> is less than a wavelength λ of an electromagnetic wave transmitted or received by the antenna of the antenna in package <NUM>, in other words, less than a wavelength corresponding to any frequency within the operating band of the antenna. Each overlay patch <NUM> is of the same size and shape, and spacings D<NUM> between two adjacent overlay patches <NUM> are the same, to provide a reflection phase closer to <NUM>° within the operating band. A shape of the overlay patch <NUM> may be a square with a side length of L<NUM>. In this case, spacings between edges of every two overlay patches <NUM> are D<NUM>. When the overlay patch <NUM> is a square, the spacing D<NUM> is a vertical distance between two nearest edges of two adjacent overlay patches <NUM> in a row or column of overlay patches <NUM>. The center of the radiation patch <NUM> (represented by a dashed box) and the center of the overlay array <NUM> are aligned in a vertical direction (or in a normal direction of the radio frequency processing chip <NUM>), so that the radiation patch <NUM> and the overlay array <NUM> obtain a more symmetric pattern characteristic. The vertical polarization feed post <NUM> and the horizontal polarization feed post <NUM> form two feed points with the radiation patch <NUM>. The two feed points are located on two orthogonal edges of the radiation patch <NUM>. To be specific, the two feed points are located on two straight lines that each are perpendicular to the edge of the radiation patch <NUM> and passing through the center of the radiation patch <NUM>, and have equal distances from the center of the radiation patch <NUM>, so as to better perform vertical polarization and horizontal polarization on an electromagnetic wave signal.

<FIG> is a top view of another overlay array <NUM>. <FIG> is different from <FIG> in that an overlay patch <NUM> in the overlay array <NUM> in <FIG> is a regular hexagon, a side length of each overlay patch <NUM> is L<NUM>, and a spacing is D<NUM>. When the overlay patch <NUM> is a regular hexagon, the spacing D<NUM> is a distance between two nearest points on edges of two adjacent overlay patches <NUM> in a row or column of overlay patches <NUM>. Similarly, the center of a radiation patch <NUM> (represented by a dashed box) and the center of the overlay array <NUM> are aligned in a vertical direction (or in a normal direction of the radio frequency processing chip <NUM>), so that the overlay array <NUM> better generates resonance. A feed point between a vertical polarization feed post <NUM> and the radiation patch <NUM> and a feed point between a horizontal polarization feed post <NUM> and the radiation patch <NUM> are located on two orthogonal edges of the radiation patch <NUM>, and have equal distances from the center of the radiation patch <NUM>, so as to better perform vertical polarization and horizontal polarization on an electromagnetic wave signal.

<FIG> is a possible reflection phase diagram of the overlay array <NUM>. A horizontal axis Freq is a frequency f of an electromagnetic wave, and a vertical axis ΔΦ<NUM> is a reflection phase ΔΦ<NUM> of the overlay array <NUM>. A reflection phase ΔΦ<NUM> of the overlay array <NUM> at a frequency f of <NUM> is <NUM>°, a point P1 in <FIG>; a reflection phase ΔΦ<NUM> at a frequency f of <NUM> is -<NUM>°, a point P2; and a reflection phase ΔΦ<NUM> at a frequency f of <NUM> is <NUM>°, a point P3. An area near the point P3 is generally referred to as a zero reflection phase region. A frequency range between the point P1 and the point P3 is a zero reflection phase characteristic region <NUM> of the overlay array <NUM>. An antenna whose operating band is from <NUM> to <NUM> is used as an example for description. When the antenna during normal operation is within the operating band, the zero reflection phase characteristic region <NUM> can always cover the operating band, so that even if the height d of the resonant cavity decreases, the overlay array <NUM> can still generate resonance and operate normally.

When the operating band required by the antenna changes, the reflection phase of the overlay array <NUM> within the operating band may be changed by adjusting the side length L<NUM> (or an area) and the spacing D<NUM> of the overlay patch <NUM>, so as to change a location of the zero reflection phase characteristic region (a region <NUM>), so that the region <NUM> can cover the operation. For example, increasing the side length L<NUM> (or the area) of the overlay patch <NUM>, or reducing the spacing D<NUM> between the overlay patches <NUM>, or increasing the side length L<NUM> (or the area) and simultaneously reducing the spacing D<NUM>, may enable the region <NUM> to translate leftward in <FIG> to cover a region <NUM>, so that the zero reflection phase characteristic region can always cover the operating band of the antenna in package <NUM>. Increasing the distance between the overlay patch <NUM> and the radiation patch <NUM> (or increasing the height d of the resonant cavity) widens the region <NUM>, to be specific, enlarges a frequency range corresponding to the zero reflection phase characteristic region, so that the zero reflection phase characteristic region better covers the operating band of the antenna in package <NUM>.

<FIG> shows a curve of an antenna gain changing with a frequency. A horizontal axis Freq is a frequency of an electromagnetic wave, and a vertical axis dB is an antenna gain. It should be noted that the antenna gain in this application is a gain of the antenna in package <NUM>. The antenna gain is approximately <NUM> dBi at a frequency f of <NUM>, a point P1 in <FIG>, and approximately <NUM> dBi at a frequency f of <NUM>, a point P2 in <FIG>. It can be learned from the gain curve in <FIG> that, in a frequency band ranging from <NUM> to <NUM>, the antenna gain is greater than <NUM> dBi, and has a relatively good gain characteristic. Increasing the spacing L between every two overlay arrays <NUM> may increase the antenna gain.

The antenna in package <NUM> may include a plurality of overlay arrays <NUM>, and the plurality of overlay arrays <NUM> are arranged in an array to further improve an antenna gain. The array arrangement may be a square array arrangement, for example, an M × M array arrangement, where M × M = N; or may be a rectangular array arrangement, for example, an M × L array arrangement (M ≠ L), where M × L = <NUM>; or may be a trapezoidal array arrangement; or may be an array arrangement of another shape.

A plurality of overlay arrays <NUM> arranged in an M × M array are used as an example for description, spacings L<NUM> between two adjacent overlay arrays <NUM> are equal, and M > <NUM>. In this case, the spacing L<NUM> is a vertical distance between two nearest edges of two adjacent overlay arrays <NUM> in a row or column of overlay arrays <NUM>. <FIG> is a top view of an antenna in package <NUM>. The antenna in package <NUM> includes <NUM> × <NUM> arrayed overlay arrays <NUM> and <NUM> × <NUM> arrayed radiation patches <NUM>. Each overlay array and one radiation patch <NUM> act as a resonant assembly to form a resonant cavity. In each resonant assembly, the center of the radiation patch <NUM> and the center of the overlay array <NUM> are aligned in a vertical direction (or in a normal direction of the radio frequency processing chip <NUM>), so that the radiation patch <NUM> and the overlay array <NUM> obtain a more symmetric pattern characteristic. A digital phase shifter in the radio frequency processing chip <NUM> may set an amplitude-phase ratio for each radiation patch <NUM>, so as to achieve a beam sweeping feature. The arrayed overlay array <NUM> and the arrayed radiation patch <NUM> may increase the antenna gain. Further, an antenna gain and a beam sweeping capability may be changed by adjusting spacings L<NUM> between every two overlay arrays <NUM>. Specifically, increasing the spacing L<NUM> may increase the antenna gain, and decreasing the spacing L<NUM> may increase a beam sweeping angle of the radiation patch <NUM>. By adjusting the spacing L<NUM> properly, the gain and the beam sweeping angle can be within an optimal range.

<FIG> shows a return loss (Return Loss) curve of an antenna obtained through simulation. A horizontal axis Freq is a frequency of an electromagnetic wave, and a vertical axis dB is a return loss of the antenna. The return loss curve corresponds to a case in which a plurality of overlay arrays <NUM> are arranged in an array. A region <NUM> is an actual operating band of the antenna, and two concave points P1 and P2 in the return loss curve are two resonance points generated by the radiation patch <NUM> and the overlay array <NUM>. It should be noted that a frequency of the resonance point generated by the radiation patch <NUM> may be less than a frequency of the resonance point generated by the overlay array <NUM>. In this case, P1 is the resonance point generated by the radiation patch <NUM>, and P2 is the resonance point generated by the overlay array <NUM>. Alternatively, a frequency of the resonance point generated by the radiation patch <NUM> may be greater than a frequency of the resonance point generated by the overlay array <NUM>. In this case, P1 is the resonance point generated by the overlay array <NUM>, and P2 is the resonance point generated by the radiation patch <NUM>. It can be learned from the return loss curve in <FIG> that, when the return loss of the antenna is less than -<NUM> dB, a frequency range covered by the antenna is approximately from <NUM> to <NUM>, and the frequency range includes all frequency bands of the <NUM> to <NUM> millimeter wave in the globe. Thus, the two resonance points generated by the overlay array <NUM> and the radiation patch <NUM> enable the antenna to obtain a wider bandwidth under the condition of a relatively low return loss.

A resonance frequency generated by the overlay array <NUM> may be changed by adjusting the side length L<NUM> (or the area) of the overlay patch <NUM>. Specifically, increasing the side length L<NUM> (or the area) may reduce the resonance frequency generated by the overlay array <NUM>, or reducing the side length L<NUM> (or the area) may increase the resonance frequency generated by the overlay array <NUM>. For example, a point P1 in <FIG> is a first resonance point generated by the overlay array <NUM>, and a point P2 is a second resonance point generated by the radiation patch <NUM>. When a frequency of the first resonance point is relatively low, a loss within the operating band range may be greater than - <NUM> dB, to affect a capability of transmitting or receive an electromagnetic wave by the antenna in package <NUM>. Therefore, the frequency of the first resonance point is increased by properly reducing the side length L<NUM> (or the area), so that a return loss characteristic (parameter S11) meets a requirement and a relatively good broadband characteristic is obtained within the operating band.

<FIG> is a schematic diagram of a sweeping characteristic of an antenna. A horizontal axis Theta is a sweeping angle during beam sweeping, and a vertical axis dB is an antenna gain. Each curve corresponds to a gain of an electromagnetic wave in the beam sweeping result. For example, a curve <NUM> in <FIG> shows an antenna gain when the sweeping angle is -<NUM>°, and the electromagnetic wave has a maximum gain of <NUM> dB when the sweeping angle is -<NUM>°. A larger angle that can be swept by the radiation patch <NUM> indicates a stronger beam sweeping capability. Reducing the spacing L<NUM> may increase the beam sweeping angle of the radiation patch <NUM>, to be specific, increase an angle of a beam that can be swept. This enhances a beam sweeping capability.

<FIG> shows a terminal device <NUM> configured to transmit, receive, and process a radio frequency signal. The terminal device <NUM> may be a mobile phone, a tablet, a portable computer, a palmtop computer, a sports band, or the like. The terminal device <NUM> includes a bus interface <NUM>, a processor <NUM>, a memory <NUM>, and a radio frequency circuit <NUM>. The processor <NUM> and the memory <NUM> are communicatively coupled, and a high-speed data transmission connection exists. The high-speed data transmission connection may be implemented by separately communicatively connecting bus interfaces <NUM> of the processor <NUM> and the memory <NUM>. The bus interface <NUM> may be a Peripheral Component Interconnect express (PCIe) interface, an Accelerated Graphical Port(AGP), or another type of bus interface. The processor <NUM> may be a central processing unit (CPU), and is configured to run a software program and/or an instruction stored in the memory <NUM>, to execute various functions of the terminal device <NUM>. Alternatively, the processor <NUM> may be an application processor (AP) and/or an image signal processor (ISP). The memory <NUM> may include a volatile memory, for example, a random access memory (RAM), or may include a non-volatile memory such as a flash memory (flash memory), a hard disk, or a solid-state drive (SSD), or may be a combination of the foregoing types of memories. In a possible implementation, the bus interface <NUM>, the processor <NUM>, and the memory <NUM> may be disposed on one Printed Circuit Board (PCB), and data is transmitted and processed by using a conductive path disposed on the PCB. Alternatively, the bus interface <NUM>, the processor <NUM>, and the memory <NUM> may be disposed on a plurality of PCBs, and data is transmitted through a general I/O interface or another communications interface. In another possible implementation, the processor <NUM> and the memory <NUM> are integrated and packed in one package apparatus.

The radio frequency circuit <NUM> includes the antenna in package <NUM> according to the embodiments of this application. In an implementation, the antenna in package <NUM> may be disposed on the PCB together with the bus interface <NUM>, the processor <NUM>, and the memory <NUM>, and is electrically connected to the PCB by using a plurality of solder balls. The antenna in package <NUM> is configured to receive an electromagnetic wave signal, convert the electromagnetic wave signal into a radio frequency signal to be processed, and transmit the processed signal to the processor <NUM>, the memory <NUM>, or another circuit. A signal in the processor <NUM>, the memory <NUM>, or another circuit may also be input to the antenna in package <NUM>, processed, converted into an electromagnetic wave signal, and then transmitted by using the antenna in package. In another implementation, the radio frequency circuit <NUM> may be integrated with at least one of the bus interface <NUM>, the processor <NUM>, or the memory <NUM> and packed into one package apparatus.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the circuit division is merely logical function division and may be other division during actual implementation. For example, a plurality of circuits or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces. The indirect couplings or communication connections between the apparatuses or circuits may be implemented in an electronic form, a mechanical form, or another form.

Claim 1:
An antenna in package (<NUM>; <NUM>), wherein the antenna in package comprises a substrate (<NUM>) and a radio frequency processing chip (<NUM>);
the radio frequency processing chip (<NUM>) is disposed on a side of the substrate, and is electrically connected to the substrate;
the substrate comprises an antenna reference ground layer (<NUM>), a signal reference ground layer (<NUM>), a signal layer (<NUM>), N radiation patches (<NUM>), N overlay arrays (<NUM>), and a feed path (<NUM>) that are disposed in the substrate; the N overlay arrays are disposed on one side of the N radiation patches to respectively form N resonant cavities, and the one side faces away from the radio frequency processing chip, and a frequency of each of the N overlay arrays when a reflection phase of the overlay arrays (<NUM>) is <NUM>° is within an operating band, wherein the operating band is a frequency range of an electromagnetic wave transmitted or received by the antenna in package during normal operation; and the radio frequency processing chip is configured to feed power to the N radiation patches through the feed path, wherein N is an integer greater than or equal to <NUM>,
wherein the overlay array is a metamaterial,
wherein the antenna in package further comprises a dielectric layer (<NUM>), and the dielectric layer (<NUM>) is configured to fill the N resonant cavities, and
wherein each of the N overlay arrays comprises a plurality of overlay patches (<NUM>) arranged in an array, and a size of each of the plurality of overlay patches (<NUM>) is less than a wavelength corresponding to any frequency within the operating band.