MULTIMODAL RETRODIRECTIVE ARRAY

• US 3,803,618 A
• Filed: 04/25/1973
• Issued: 04/09/1974
• Est. Priority Date: 04/25/1973
• Status: Expired due to Term

• Current Assignee: Coleman H. Paris
• Original Assignee: Coleman H. Paris
• Inventors: Coleman, H. Paris
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/354,403
• Time in Patent Office: 349 Days
• Field of Search: 343/1TD,753,754,854,893
• US Class Current: 343/754
• CPC Class Codes: H01Q 3/2647 Retrodirective arrays

Abstract

A technique and apparatus for obtaining automatic retrodirective performance from antennas and antenna arrays of general geometric configurations such as cones, ellipsoids, etc. The elements of the antennas or arrays are connected to multimodal feed networks. Conjugate phase circuits and gain adjustments are connected to some of the feed network terminals. The degree of retrodirectivity can be controlled by the gain adjustment and the number of conjugate phase circuits used.

Claims

1. A retrodirective antenna system of general geometric configuration comprising:

a plurality of stacked circularly symmetric antennas;

a like plurality of multimodal feed networks having antenna terminals and mode terminals, each symmetric antenna being associated with one of said multimodal networks;

means for connecting each individual antenna in each symmetric antenna to the antenna terminals of the associated network; and

, means connected to the mode terminals of said networks for receiving a signal from a terminal and returning to the terminal the phase conjugate of said signal.

2. The retrodirective antenna system of claim 1 wherein said circularly symmetric antennas are circular arrays.

3. The retrodirective antenna system of claim 1 wherein said circularly symmetric antennas are continuous aperture antennas.

4. The retrodirective antenna system of claim 1 wherein each of said multimodal feed networks is a Butler-Shelton matrix.

5. The retrodirective antenna system of claim 1 wherein each of said circularly symmetric antennas has a different axis.

6. The retrodirective antenna system of claim 2 wherein each of said circular arrays has a different number of elements.

7. The retrodirective antenna system of claim 1 wherein said signal receiving and returning means includes at least one conjugate phase circuit and one gain adjustment circuit.

8. The retrodirective antenna system of claim 7 wherein those mode terminals which are not connected to a conjugate phase circuit and gain adjustment circuit are terminated in matched loads.