Two-dimensional planar and crossover-free beamforming network architecture

Patent metadata

Field	Value
Publication number	US-11699862-B2
Application number	US-202117407755-A
Country	US
Kind code	B2
Filing date	Aug 20, 2021
Priority date	Aug 21, 2020
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

An antenna system has a two-dimensional field of view, yet can be implemented on a surface, such as on electronic or photonic integrated circuits. The antenna system includes an array of antennas disposed in a predetermined non-linear pattern and a two-dimensional beamforming network (BFN). The antenna system can be steered/selectively beamformed in two dimensions through beam port selection. The beamforming network is disposed entirely on a single first surface. The beamforming network has a one-dimensional array-side interface disposed on the first surface and a one-dimensional beam-side interface disposed on the first surface. The antennas of the array of antennas are individually communicably coupled to the array-side interface. Segments of the beam-side interface map to respective pixels in the two-dimensional field of view.

First claim

What is claimed is:

1. An antenna system comprising:
an array of antennas disposed in a predetermined non-linear pattern, the array of antennas comprising a plurality of antennas and having a two-dimensional field of view; and
a two-dimensional beamforming network (BFN) disposed entirely on a single first surface, and having a one-dimensional array-side interface disposed on the first surface and a one-dimensional beam-side interface disposed on the first surface; wherein:
the antennas of the array of antennas are individually communicably coupled to the array-side interface, such that segments of the beam-side interface map to respective pixels in the two-dimensional field of view;
the predetermined non-linear pattern defines a second surface;
the array of antennas comprises a plurality of disjoint sets of antennas;
each disjoint set of antennas comprises a plurality of antennas of the array of antennas; and
for each disjoint set of antennas, each antenna of at least a non-empty subset of the disjoint set of antennas is perpendicularly displaced a respective distance along the second surface from a longitudinal axis of a hypothetical linear array of antennas disposed on the second surface.

2. An antenna system according to claim 1 , wherein the array of antennas and the two-dimensional beamforming network collectively form a true time delay system.

3. An antenna system according to claim 1 , wherein the one-dimensional array-side interface is segmented.

4. An antenna system according to claim 1 , wherein the one-dimensional beam-side interface is continuous.

5. An antenna system according to claim 1 , wherein the first surface is planar.

6. An antenna system according to claim 1 , wherein the first surface is non-planar.

7. An antenna system according to claim 1 , wherein the first surface is folded.

8. An antenna system according to claim 1 , wherein the predetermined non-linear pattern defines a second surface that extends smoothly from an edge of the first surface.

9. An antenna system according to claim 8 , wherein:
the predetermined non-linear pattern defines a second surface; and
the array of antennas is communicably coupled to the array-side interface via a crossover-free network disposed entirely on the first and/or second surface.

10. An antenna system according to claim 1 , wherein:
the antenna system has a design wavelength λ;
the plurality of disjoint sets of antennas comprises N disjoint sets of antennas; and
within each disjoint set of the antennas:
the antennas are spaced apart in a direction parallel to the longitudinal axis of the hypothetical linear array of antennas, wherein spacing between each pair of adjacent antennas is an integral multiple of about ½λ; and
the antennas are spaced apart in a direction perpendicular to the longitudinal axis of the hypothetical linear array of antennas.

11. An antenna system according to claim 10 , wherein:
the antenna system has a design wavelength λ; and
within each disjoint set of the antennas:
the antennas are spaced apart by respective integral multiples of (λ/2) in the direction parallel to the longitudinal axis; and
the antennas are spaced apart by respective integral multiples of (λ/2) in the direction perpendicular to the longitudinal axis.

12. An antenna system according to claim 1 , wherein:
the predetermined non-linear pattern defines a second surface;
the array of antennas comprises a plurality of disjoint sets of antennas;
each disjoint set of antennas comprises a plurality of antennas of the array of antennas; and
for each disjoint set of antennas, each antenna of at least a non-empty subset of the disjoint set of antennas is displaced a respective distance, measured along the second surface and parallel to one dimension of the two-dimensional field of view, from a longitudinal axis of a hypothetical linear array of antennas disposed on the second surface.

13. An antenna system according to claim 12 , wherein:
the antenna system has a design wavelength λ;
the plurality of disjoint sets of antennas comprises N disjoint sets of antennas; and
within each disjoint set of the antennas:
the antennas are spaced apart in a direction parallel to the longitudinal axis of the hypothetical linear array of antennas, wherein spacing between each pair of adjacent antennas is an integral multiple of about ½λ; and
the antennas are spaced apart in a direction perpendicular to the longitudinal axis of the hypothetical linear array of antennas.

14. An antenna system according to claim 12 , wherein:
the antenna system has a design wavelength λ; and
within each disjoint set of the antennas:
the antennas are spaced apart by respective integral multiples of (λ/2) in the direction parallel to the longitudinal axis; and
the antennas are spaced apart by respective integral multiples of (λ/2) in the direction perpendicular to the longitudinal axis.

15. An antenna system according to claim 1 , wherein the antenna system has a design wavelength between about 10 nanometers and about 1 millimeter.

16. An antenna system according to claim 1 , wherein the antenna system has a design wavelength between about 1 millimeter and about 100 meters.

17. An antenna system according to claim 1 , wherein:
the predetermined non-linear pattern defines a second surface; and
each antenna of the array of antennas comprises a grating coupler configured to optically couple to free space beyond the second surface with a coupling efficiency of at least about 25%.

18. An antenna system according to claim 1 , wherein the two-dimensional beamforming network comprises a Rotman lens.

19. An antenna system according to claim 1 , wherein the two-dimensional beamforming network comprises a Fourier transformer.

20. An antenna system according to claim 1 , wherein the two-dimensional beamforming network comprises a Butler matrix.

21. An antenna system according to claim 1 , wherein the two-dimensional beamforming network comprises a single-stage beamforming network.

22. An antenna system according to claim 1 , wherein the two-dimensional beamforming network comprises a single Rotman lens.

23. An antenna system according to claim 1 , wherein:
the array of antennas comprises N (N>1) disjoint sets of antennas;
each disjoint set of antennas comprises a plurality of antennas of the array of antennas; and
the two-dimensional beamforming network comprises:
N first beamforming networks, each first beamforming network being associated with a distinct set of the antennas and having a beam-side interface and a plurality of array-side ports, wherein the array-side ports of each first beamforming network are individually communicably coupled to respective antennas of the associated set of the antennas, the array-side ports of the N first beamforming networks thereby collectively forming the one-dimensional array-side interface of the two-dimensional beamforming network;
N second beamforming networks, each second beamforming network being associated with a distinct first beamforming network and having an array-side interface and a beam-side interface, wherein the beam-side interface of each second beamforming network is communicably coupled to the beam-side interface of the associated first beamforming network; and
a third beamforming network having an array-side interface and a plurality of beam-side ports, wherein the array-side interface of each second beamforming network is communicably coupled to

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Brown Julian A
• Lane Benjamin F
• Clevenson Hannah
• Benney Lucas D
• Moebius Michael G
• Dawson Robin M A
• Spector Steven J

Classifications

• H01Q21/12 Primary

  Parallel arrangements of substantially straight elongated conductive units (travelling-wave antennas comprising transmission line loaded with transverse elements H01Q11/02; Yagi antennas H01Q19/30) · CPC title

• H01Q1/246

  specially adapted for base stations · CPC title

• H01Q3/40 Primary

  with phasing matrix · CPC title

• H01Q11/14

  with parts bent, folded, shaped or screened or with phasing impedances, to obtain desired phase relation of radiation from selected sections of the antenna or to obtain desired polarisation effect (H01Q11/20 takes precedence) · CPC title

• H01Q21/061

  Two dimensional planar arrays · CPC title