Phased array systems and phased array front-end devices

• US 7,728,772 B2
• Filed: 06/09/2006
• Issued: 06/01/2010
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: University of Michigan
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Schulwitz, Lora S., Mortazawi, Amir
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Nguyen; Nga X
• Application Number:
  US11/449,925
• Publication Number:
  US 20070285314A1
• Time in Patent Office: 1,453 Days
• Field of Search: 327/404, 343/854, 343/754, 343/853, 343/858, 343/910, 343/111.R, 343/911, 342/81, 342/154, 342368-375
• US Class Current: 342/375
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: H01Q 1/3233 particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems
• CPC Class Codes: H01Q 15/06 comprising plurality of wave-guiding channels of different length
• CPC Class Codes: H01Q 21/0031 Parallel-plate fed arrays; Lens-fed arrays multibeam arrays H01Q25/008
• CPC Class Codes: H01Q 21/064 using horn or slot aerials slotted waveguides arrays H01Q21/005
• CPC Class Codes: H01Q 21/245 provided with means for varying the polarisation polarising devices H01Q15/24; tracking by comparing linear polarisation compounds G01S3/146; reducing depolarisation effects H04B7/00; polarisation diversity H04B7/10

Abstract

Disclosed herein is a front-end device for a phased array system. The front-end device includes an array of horn antennas, a first set of transmission lines coupled to the horn antenna array for a first polarization, a second set of transmission lines coupled to the horn antenna array for a second polarization orthogonal to the first polarization, and a plurality of L-shaped excitation elements. Each L-shaped excitation element of the plurality of L-shaped excitation elements couples a transmission line from each of the first and second sets of transmission lines to a respective horn antenna of the horn antenna array.

Claims

1. A front-end device for a phased array system, comprising:

an antenna array; and

,

a phase-shifting network to couple the antenna array to the phased array system;

wherein the phase-shifting network comprises a Rotman lens having a plurality of beam ports and a plurality of array ports and a plurality of regions each varying in a material property from another, wherein the regions extend from an inner portion of the Rotman lens to a peripheral portion of the Rotman lens; and

,

wherein any signals passing between one or more of the plurality of beam ports and one or more of the plurality of array ports encounter the varying material property within the Rotman lens.

2. The front-end device of claim 1, wherein the material property is permittivity such that a permittivity variation enhances focusing within the Rotman lens.

3. The front-end device of claim 2, wherein the Rotman lens comprises a microstrip and a substrate on which the microstrip is disposed, and wherein the substrate comprises a hole distribution to effect the permittivity variation.

4. The front-end device of claim 3, wherein the hole distribution comprises a lattice of holes filled with a number of dielectric materials.

5. The front-end device of claim 2, wherein the Rotman lens comprises a housing defining a cavity through which the signals pass, and wherein the cavity is filled with a number of dielectric materials to effect the permittivity variation.

6. The front-end device of claim 2, wherein the Rotman lens comprises the plurality of regions, each of which has a different permittivity to effect the permittivity variation.

7. The front-end device of claim 6, wherein the plurality of regions are wedge-shaped.

8. The front-end device of claim 2, wherein the Rotman lens comprises a dielectric component having a continuously varying dielectric constant, such that the permittivity variation has a continuous gradient.

9. The front-end device of claim 1, wherein the material property is permittivity and wherein each of the plurality of regions is adjacent to another of the plurality of regions such that permittivity increases along a signal path in the Rotman lens.

10. The front-end device of claim 1, wherein each of the plurality of regions vary in permittivity, and wherein at least some of the plurality of regions vary in shape.

11. The front-end device of claim 10, wherein the variation in the material property is such that the Rotman lens is able to maintain less than 10 dB sidelobes with respect to a main beam across all scan angles.

12. The front-end device of claim 1, wherein each of the plurality of regions is formed of the same dielectric material and wherein each of the plurality of regions has a different hole distribution to effect the permittivity variation.

13. A front-end device for a phased array system, comprising:

an antenna array; and

,

a phase-shifting network to couple the antenna array to the phased array system;

wherein the phase-shifting network comprises a Rotman lens having a plurality of beam ports and a plurality of array ports and a plurality of regions each varying in a material property from another, the plurality of regions being configured such that all signals passing between the plurality of beam ports and the plurality of array ports encounter at least two regions of varying material property from one another.

14. The front-end device of claim 13, wherein the material property is permittivity such that a permittivity variation enhances focusing within the Rotman lens.

15. The front-end device of claim 13, wherein the Rotman lens comprises a housing defining a cavity through which the signals pass, and wherein the cavity is filled with a number of dielectric materials to effect the permittivity variation.

16. The front-end device of claim 13, wherein the Rotman lens comprises the plurality of regions, each of which has a different permittivity to effect the permittivity variation.

17. The front-end device of claim 13, wherein the Rotman lens comprises a dielectric component having a continuously varying dielectric constant, such that the permittivity variation has a continuous gradient.

18. The front-end device of claim 13, wherein the material property is permittivity and wherein each of the plurality of regions is adjacent to another of the plurality of regions such that permittivity increases along a signal path in the Rotman lens.

19. The front-end device of claim 13, wherein the variation in the material property is such that the Rotman lens is able to maintain less than 10 dB sidelobes with respect to a main beam across all scan angles.

20. A front-end device for a phased array system, comprising:

an antenna array; and

,

a phase-shifting network to couple the antenna array to the phased array system;

wherein the phase-shifting network comprises a Rotman lens having (i) a plurality of beam ports each sharing a beam port region having a first material property, (ii) a plurality of array ports each sharing an array port region having a second material property different than the first, and (iii) a plurality of regions between the beam port region and the array port region and each varying in a material property from another and from the first material property and the second material property.