Patent Application
20080106467
This disclosure relates to electronically scanned antennas, and more particularly to compact, low-profile architecture for electronically scanned antennas.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Electronically scanned antennas, also commonly referred to as phased array antennas, are comprised of multiple radiating antenna elements, individual element control circuits, a signal distribution network, signal control circuitry, a power supply and a mechanical support structure. The total gain, effective isotropic radiated power (“EIRP”) (with a transmit antenna) and scanning and side lobe requirements of the antenna are directly related to the number of elements in the antenna aperture, the individual element spacing and the performance of the elements and element electronics. In many applications, thousands of independent element/control circuits are required to achieve a desired antenna performance.
A phased array antenna typically requires independent electronic packages for the radiating elements and control circuits that are interconnected through a series of external connectors. As the antenna operating frequency (or beam scan angle) increases, the required spacing between the phased array radiating elements decreases. As the spacing of the elements decreases, it becomes increasingly difficult to physically configure the control electronics relative to the tight element spacing. This can affect the performance of the antenna and/or increase its cost, size and complexity. Consequently, the performance of a phased array antenna becomes limited by the need to tightly package and provide vertical interconnects from the electronics to the RF distribution network and radiating elements. As the number of radiating elements increases, the corresponding increase in the required number of external connectors (i.e., “interconnects”) serves to significantly increase the cost of the antenna.
Additionally, multiple beam antenna applications further complicate this problem by requiring more electronic components and circuits to be packaged within the same module spacing. Conventional packaging approaches for such applications result in complex, multi-layered interconnect structures with significant cost, size and weight.
The tile architecture approach can be implemented for individual elements or for an array of elements. Additionally, the traditional tile architecture approach has the ability to support dual polarization radiators as a result of its coplanar orientation relative to the antenna aperture. Individual element tile configurations can also allow for complete testing of a functional element prior to antenna integration. Ideally, the tile configuration lends itself to most manufacturing processes and has the best potential for low cost if the electronics can be accommodated for a given element spacing. However, this configuration requires discrete interconnects for each layer in the structure, where the number of interconnects required is directly in accordance with the number of radiating elements of the antenna. Additionally, the mechanical construction of the individual tiles in the array typically contribute to limitations on the minimum element spacing that can be achieved.
A tile architecture configuration for a phased array antenna can also be implemented in multiple element configurations. As such, the tile architecture approach can take advantage of distributed, routed interconnects resulting in fewer components at the intermediate plane 12. The tile architecture approach also takes advantage of mass alignment techniques providing opportunities for lower cost antennas. The multiple element configuration, however, does not support individual element testing and consequently is more severely impacted by process yield issues confronted in the manufacturing process. Conventional enhancements to the basic tile architecture approach have involved multiple layers of interconnects and components, which increases antenna cost and complexity.
The assignee of the present application is a leading innovator in phased array antenna packaging and manufacturing processes involving modified tile and brick packaging architectures. The prior work of the assignee in this area is described in U.S. Pat. No. 5,886,671 to Riemer et al, issued Mar. 23, 1999 and U.S. Pat. No. 5,276,455 to Fitzsimmons et al, issued Jan. 2, 1994. The disclosures of both of these patents are hereby incorporated by reference into the present application. While the approaches described in these two patents address many of the issues and limitations of tile and brick packaging architectures, these approaches are still space limited as the frequency increases.
Accordingly, there is a need for a packaging architecture for a phased array antenna module which permits even closer radiating element spacing to be achieved, and which allows for even simpler and more cost efficient manufacturing processes to be employed to produce a phased array antenna.
A compact, low profile electronically scanned antenna module is provided. In accordance with various embodiments, the antenna module includes a multi-layer antenna integrated printed wiring board (AiPWB) that includes a radiator layer on a front surface. The radiator layer includes a plurality of RF radiating elements. The antenna module additionally includes a plurality of radiator electronics modules orthogonally connected to a back surface of the AiPWB. The electronics modules are interconnected with radiating elements through the AiPWB and include a plurality of beam steering electronic elements mounted to a multi layer conformable substrate. The orthogonal connections allow the antenna module to have outer dimensions that are substantially equal to the dimensions of a perimeter of the AiPWB. Additionally, frequency and scanning angle requirements of the antenna module can be increased by merely increasing the length of the electronics modules in the orthogonal direction to allow for additional beam steering electronic elements needed to accommodate the increased frequency and scanning requirements.
Further areas of applicability of the present teachings will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present teachings.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present teachings in any way.
The following description is merely exemplary in nature and is in no way intended to limit the present teachings, application, or uses. Throughout this specification, like reference numerals will be used to refer to like elements.
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The conformable substrate 82 can be formed in a variety of shapes during assembly such that the resulting electronics modules 44 can be adapted for implementation in a wide variety of antenna configurations to suit specific applications. For example, in accordance with various embodiments, the substrate 82 is populated with the beam steering electronic elements 90 with the substrate 82 in a substantially flat configuration (
As will be appreciated, the integrally formed monolithic transmission lines 45 and feed transmission lines 50 eliminate the need for external interconnects, thus significantly reducing the overall manufacturing complexity and overall cost of the antenna module 40. Additionally, as described above, the beam steering electronic elements 90 are positioned vertically with respect to the AiPWB 42. Accordingly, an antenna aperture, formed by outer perimeter dimensions of the AiPWB 42, is also orthogonal to the plane on which the electronics modules 44, and thus, the beam steering electronic elements 90, are oriented. Since the electronics modules 44 are substantially orthogonally connected to the AiPWB 42, the outer dimensions of the antenna module 40 are substantially equal to the dimensions of a perimeter of the AiPWB 24.
Each wing panel 102 includes beam steering electronics 90 associated with at least one radiator element 50. More specifically, the beam steering elements 90 on each wing panel 102 independently operate to control the beam steering and transmission processing, and/or signal reception processing for at least one radiator element 50. Thus, each electronics module 44 includes two separate radiator beam steering control circuits 110, one on each wing panel 102, that controls the beam steering and transmission processing, and/or signal reception processing for at least two radiator elements 50. For example, in various embodiments, the interconnected beam steering electronic elements 90 on each wing panel 102 can comprise a separate radiator beam steering control circuit 110, i.e., two separate beam steering control circuits 110, wherein each beam steering control circuit 110 is associated with, and controls beam steering and signal processing of one of the radiator elements 50. Alternatively, in various embodiments, the interconnected beam steering electronic elements 90 on each wing panel 102 can comprise a separate radiator beam steering control 110, i.e., two separate beam steering control circuits 110, wherein each beam steering control circuit 110 is associated with, and controls beam steering and signal processing of a selected group of two or more radiators 50.
Furthermore, it should be understood that although
The orthogonal positional relationship between the AiPWB 42 and the radiator electronics modules 44 provides a significantly increased availability of chip attachment area per radiating element 50. That is, since each radiator electronics module 44 is orthogonally connected to and extends orthogonally from, the AiPWB 42, each wing panel 102 can have generally any length L, along the Z axis, needed to mount all the beam steering electronic elements 90 necessary to accommodate the desired scanning angle and frequency of the respective antenna module 40, for any specific application. More particularly, as the desired scanning angle and frequency of the respective antenna module 40 increase, so also do the number of beam steering electronic elements 90. By orthogonally connecting the electronics modules 42 to the AiPWB 42, the length L of the wing panels 102 can be configured to generally any length necessary to accommodate all the electronic elements 90 needed to meet the desired scanning angle and frequency requirements. Accordingly, since the antenna module 40 can be longitudinally ‘grown’, or expanded, along the Z axis, away from the AiPWB 42, the antenna module 40 can provide generally any desired beam steering angle, frequency and performance specification without increasing the perimeter dimensions of the AiPWB 42. Thus, the aperture of the antenna module 40 will remain the same regardless of the complexity, beam steering angle, frequency and performance of the antenna module 40 of the specific application. Furthermore, functionality and complexity of the AiPWB 42 can be added by merely adding additional layers to the AiPWB 42 without increasing the size of the AiPWB 42 and thus the size of the antenna aperture.
It should be understood that the phased array antenna module 40, as described herein, can be utilized in full-duplex communication applications, to provide either transmit or receive functions. Or, the phased array antenna module 40, as described herein, can be utilized in half-duplex communication and radar sensor applications, to provide both transmit and receive functions selectable through a switch or circulator.
The packaging architecture of the antenna module 40, described herein, allows for wider, more consistent beam steering at higher operating frequencies by providing ‘growth’ or expansion in the Z direction. As described, the antenna module 40 can be utilized as a transmit/receive module which can be used for radar sensor applications as well as half-duplex communication systems well into millimeter wavelengths.
From the foregoing, it will be appreciated that the conformable substrate 82, described herein, lends itself readily to a variety of implementations. Importantly, the elimination of large pluralities of external interconnects allows extremely tight radiating element spacing to be achieved, while also reducing the cost and manufacturing complexity of a high frequency phased array antenna incorporating the radiator electronics module 42. This enables phased array antennas having large pluralities of radiating elements to be constructed even more cost effectively than with previously developed packaging architectures. As a result, the antenna module 40, described herein, allows electronically scanned, phased array antennas to be used in a variety of implementations where previously developed packaging architectures would have resulted in an antenna that would be too costly to implement.
The description herein is merely exemplary in nature and, thus, variations that do not depart from the gist of that which is described are intended to be within the scope of the teachings. Such variations are not to be regarded as a departure from the spirit and scope of the teachings.
