Wide frequency range dual polarized radiating element with integrated radome

A low-profile array and a low-profile radiating element including: a stripline feed layer; a High Order Floquet (HOFS) part layer; and a radome layer in direct contact with the HOFS part layer, where the HOFS part layer is disposed between the stripline feed layer and the radome layer, and the radome layer includes a high dielectric constant (dk) environmentally robust material.

FIELD

The present invention is directed generally toward antennas, and more particularly to electronically scanned antennas.

BACKGROUND

Current planar radiating element technology cannot provide a low-profile radiating element with relatively wide frequency range and scan volume and good polarization performance. A low profile dual polarized radiating element with an integrated radome having relatively wide frequency range and scan volume would be preferable.

SUMMARY

Accordingly, embodiments are directed to a novel apparatus that is a High Order Floquet (HOFS) wide frequency range dual polarized radiating element with an integrated radome. In some embodiments, the frequency range spans 10.7 to 14.5 GHz. In some embodiments, the dual polarization is provided as a horizontal and vertical polarization. In some embodiments, the integrated radome may include a high dielectric coefficient environmentally robust material, for example, quartz.

One general aspect includes a low-profile radiating element including: a stripline feed layer; a High Order Floquet (HOFS) part layer; and a radome layer in direct contact with the HOFS part layer, where the HOFS part layer is disposed between the stripline feed layer and the radome layer, and the radome layer includes a high dielectric constant (dk) environmentally robust material.

Implementations may include one or more of the following features. The radiating element where the HOFS part layer includes a first cluster of metallic striplines, generally elongated along a first axis, configured to produce a first signal having a first polarization. The radiating element may also include a second cluster of metallic striplines, generally elongated along a second axis substantially orthogonal to the first axis, configured to produce a second signal having a second polarization substantially orthogonal to the first polarization, where the first cluster is segregated from the second cluster. The radiating element where the first cluster is disposed in an equilateral triangular grid array. The radiating element where the radiating element is configured to operate in a frequency range including 10.7 to 14.5 GHz. The radiating element where the radiating element is configured to operate with a scan angle θ from 0° to 45° and a φ scan angle from 0° and 360°. The radiating element where the dielectric constant of the HOFS part layer is between 3.3 and 3.7. The radiating element where the radome layer includes a quartz layer and is integrated with the HOFS part layer. The radiating element where there is no gap between the HOFS part layer and the radome layer. The radiating element where the HOFS part layer includes a low loss FR-4 material such as Rogers 4003 or Megtron 6. The radiating element where the stripline feed layer, the HOFS part layer and the radome layer together form a PCB stack having a cross-section depth is less than or equal to 100 mils (2.54 millimeter).

One general aspect includes an array including: a plurality of low-profile radiating elements, each radiating element including a stripline feed layer; a High Order Floquet (HOFS) part layer; and a radome layer in direct contact with the HOFS part layer, where the HOFS part layer is disposed between the stripline feed layer and the radome layer, the radome layer includes a high dielectric constant (dk) environmentally robust material, and the radiating elements are arranged in an equilateral triangular array.

Implementations may include one or more of the following features. The array where the radome layer includes a layer of quartz. The array where the low-profile radiating element is configured to operate in Ku and X frequency bands. The array where the low-profile radiating element is configured to operate in a frequency range including 10.7 to 14.5 GHz with a scan angle θ from 0° to 45° and a φ scan angle from 0°≤φ≤360°. The array further including an upper metallization layer including a plurality of metallic striplines organized with substantial bilateral symmetry along both a first axis and a second axis orthogonal to the first axis.

Additional features will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of what is described.

DETAILED DESCRIPTION

Embodiments are discussed in detail below. While specific implementations are discussed, this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the subject matter of this disclosure.

The terminology used herein is for describing embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, the use of the terms “a,” “an,” etc. does not denote a limitation of quantity but rather denotes the presence of at least one of the referenced items. The use of the terms “first,” “second,” and the like does not imply any order, but they are included to either identify individual elements or to distinguish one element from another. It will be further understood that the terms “comprises” and/or “comprising”, or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. Although some features may be described with respect to individual exemplary embodiments, aspects need not be limited thereto such that features from one or more exemplary embodiments may be combinable with other features from one or more exemplary embodiments.

A low-profile antenna that includes a low-profile radiating element is desirable in many applications including aero applications. An integrated radome for the low-profile radiating element permits a low-profile deployment and reduces air drag induced by the airborne antenna. Moreover, low profile antennas are important for packaging and other deployments.

The low-profile radiating elements may be used in antennas that operate in a wide frequency range with large scan volume requirements such as satellite systems like the Low-Earth Orbit or Mid-Earth Orbit satellite systems. that need. The low-profile radiating elements may be used for vehicular and aeronautical applications in Low-Earth Orbit, Mid-Earth Orbit, Geosynchronous Earth Orbit, High Altitude Platform satellite systems.

FIG.1shows a cross-sectional side view of a radiating element including a radome integrated with a PCB stack according to various embodiments.

Referring toFIG.1, a radiating element100includes a stripline feed layer104, a High Order Floquet (HOFS) part layer102connected to the stripline feed layer104and a radome layer106connected to the HOFS part layer102. The stripline feed layer104includes a first core110and a second core112. The HOFS part layer102includes a first layer120and a second layer122. The radiating element100may be implemented as a printed circuit board (PCB) stack108. The PCB stack108may be manufactured with the radome layer106such that there is no air gap between the radome layer106and the PCB stack108. In some embodiments, the PCB stack108and the radome layer106are in direct contact. The PCB stack108includes the HOFS part layer102and the stripline feed layer104. Each of the first core110, the second core112, the first layer120and the second layer122may include printed circuit patterns. In some embodiments, a coupling from the HOFS part layer102to the stripline feed layer104is through slots (seeFIG.2) cut in a top ground plane of the stripline feed layer104.

In some embodiments, an electronically scanned antenna including a plurality of the radiating elements disposed in an equilateral triangle grid array (seeFIG.15) may be implemented with the printed circuit board (PCB) stack108. A cross-section depth124of the PCB stack108. The HOFS part layer102has a number of printed circuit board layers; all printed circuit board layers include a high dielectric constant material suitable for FR-4 or Megtron 6 manufacturing processes. The printed circuit board is balanced to reduce warping.

In some embodiments, a thickness of the radome layer106of the radiating element100may be as little as 20 mil (0.508 mm). The first layer120of the HOFS part layer102may have a thickness of 10 mil (0.254 mm) and the second layer122of the HOFS part layer102may have s a thickness of 30 mil (0.762 mm). The first core110of the stripline feed layer104may have a thickness of about 20 mil (0.508 millimeters) and the second core112of the stripline feed layer104may have a thickness of about 20 mil (0.508 millimeters). In some embodiments, a stack height of the PCB stack108(layers including the HOFS part layer102, the stripline feed layer104and the radome layer106) maybe less than or equal to 100 mils (2.54 mm). In some embodiments, the radiating elements may be disposed in an equilateral triangle grid array. Such an embodiment scans well over a wide frequency range and offers low cross-polar radiation.

The stripline feed layer104and the HOFS part layer102may include a high dielectric constant material such as Rogers 4003, Rogers 3003, Rogers 5880 LZ or similar material. Rogers 3003 and Rogers 5880 LZ are exemplary Teflon based materials. Rogers 4003 is an exemplary low cost and low loss FR-4 based material. Herein, high dielectric constant may be understood to refer generally to a dielectric greater than 3.3. Embodiments of the present invention are directed specifically toward materials with a dielectric constant of between 3.3 and 3.7, though a person of ordinary skill in the art having the benefit of the disclosure may appreciate that other dielectric constants are envisioned.

FIG.2shows a top view of a stripline feed layer and ground plane with two slots of a dual polarized radiating element according to various embodiments.

FIG.2illustrates a radiating element cell200formed in a ground plane layer202. may include metal therein to define a horizontal stripline feed206and a vertical stripline feed210. The ground plane layer202may define an imaginary triangular grid unit cell boundary220for the radiating element cell200.

The horizontal stripline feed206may be disposed below a horizontal polarization ground plane slot208formed by a high dielectric constant material204. Portions of the high dielectric constant material204may lay outside the imaginary triangular grid unit cell boundary220.

The vertical stripline feed210may be disposed below a vertical polarization ground plane slot212formed by a high dielectric constant material214. Portions of the high dielectric constant material214may lay outside the triangular grid unit cell boundary220.

FIG.3shows a top view of a lower metallization layer of a radiating element according to various embodiments.

Referring toFIG.3, a radiating element300includes a HOFS layer on a dielectric material substrate, for example, Rogers 4003. The a HOFS layer302includes a plurality of metallic squares304, organized to tune the radiating element in a particular frequency range and balance additional metal layers as described herein.

FIG.4shows a top view of an upper metallization layer of a radiating element according to various embodiments.

Referring toFIG.4, a radiating element400includes an upper metallization layer (HOFS layer)402on a dielectric material substrate such as Rogers 4003. The upper metallization layer402includes a plurality of metallic squares404, organized to tune the radiating element in a particular frequency range and balance additional metal layers as described herein.

Referring toFIG.5, a Smith chart500illustrates the performance of a radiating element operating with θ (theta) of 0 degrees and φ (phi) of 0 degrees is shown in a frequency range of 10.7 to 14.5 GHz. Performance is measured as return loss in decibels. Return loss is shown for a horizontal polarization504and a vertical polarization502.

Referring toFIG.6, a rectangular plot600illustrates the performance of a radiating element operating with θ (theta) of 0 degrees and φ (phi) of 0 degrees is shown in a frequency range of 10.7 to 14.5 GHz. Performance is measured as return loss in decibels. Return loss is shown for a horizontal polarization604and a vertical polarization602.

Referring toFIG.7, a Smith chart700illustrates the performance of a radiating element operating with θ (theta) of 45 degrees and φ (phi) of 0 degrees is shown in a frequency range of 10.7 to 14.5 GHz. Performance is measured as return loss in decibels. Return loss is shown for a horizontal polarization704and a vertical polarization702.

Referring toFIG.8, a rectangular plot800illustrates the performance of a radiating element operating with θ (theta) of 45 degrees and φ (phi) of 0 degrees is shown in a frequency range of 10.7 to 14.5 GHz. Performance is measured as return loss in decibels. Return loss is shown for a horizontal polarization804and a vertical polarization802.

Referring toFIG.9, a Smith chart900illustrates the performance of a radiating element operating with θ (theta) of 45 degrees and φ (phi) of 30 degrees is shown in a frequency range of 10.7 to 14.5 GHz. Performance is measured as return loss in decibels. Return loss is shown for a horizontal polarization904and a vertical polarization902.

Referring toFIG.10, a rectangular plot1000illustrates the performance of a radiating element operating with θ (theta) of 45 degrees and φ (phi) of 30 degrees is shown in a frequency range of 10.7 to 14.5 GHz. Performance is measured as return loss in decibels. Return loss is shown for a horizontal polarization1004and a vertical polarization1002.

Referring toFIG.11, a Smith chart1100illustrates the performance of a radiating element operating with θ (theta) of 45 degrees and φ (phi) of 60 degrees is shown in a frequency range of 10.7 to 14.5 GHz. Performance is measured as return loss in decibels. Return loss is shown for a horizontal polarization1104and a vertical polarization1102.

Referring toFIG.12, a rectangular plot1200illustrates the performance of a radiating element operating with θ (theta) of 45 degrees and φ (phi) of 60 degrees is shown in a frequency range of 10.7 to 14.5 GHz. Performance is measured as return loss in decibels. Return loss is shown for a horizontal polarization1204and a vertical polarization1202.

Referring toFIG.13, a Smith chart1300illustrates the performance of a radiating element operating with θ (theta) of 45 degrees and φ (phi) of 90 degrees is shown in a frequency range of 10.7 to 14.5 GHz. Performance is measured as return loss in decibels. Return loss is shown for a horizontal polarization1304and a vertical polarization1302.

Referring toFIG.14, a rectangular plot1400illustrates the performance of a radiating element operating with θ (theta) of 45 degrees and φ (phi) of 90 degrees is shown in a frequency range of 10.7 to 14.5 GHz. Performance is measured as return loss in decibels. Return loss is shown for a horizontal polarization1404and a vertical polarization1402.

FIG.15illustrates an array including radiating elements disposed in an equilateral triangular grid array according to various embodiments.

FIG.15illustrates an array1500including radiating elements1502are segregated and disposed in an equilateral triangular grid array. To form the array1500, adjacent radiating elements1502may be disposed at a distance of a along the H-axis (horizontal), and at a distance of a√{square root over (3)}/2 along the V-axis (vertical). Each row or column of the radiating elements1502maybe viewed as a cluster, for example.

FIG.16illustrates an enlargement of the array ofFIG.15.

An equilateral triangular array1600may include a plurality of radiating element cells1606. Each of the radiating element cells1606may include a horizontal stripline1602and a vertical stripline1604. Each of the radiating element cells1606may be defined by an imaginary boundary1608.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. Other configurations of the described embodiments are part of the scope of this disclosure. Further, implementations consistent with the subject matter of this disclosure may have more or fewer acts than as described or may implement acts in a different order than as shown. Accordingly, the appended claims and their legal equivalents should only define the invention, rather than any specific examples given.