Self-directional Microwave Communication System

Abstract

This paper describes a communication system in which sending and receiving terminals automatically generate beams focused upon each other, which arise solely from ambient noise. The terminals are amplifying retrodirective arrays of antenna elements. Analysis and experiment are used to prove and verify the system concept. Some engineering considerations pertinent to system operation under various conditions are also analyzed and discussed.

Accurate Multibias Equivalent-Circuit Extraction for GaN HEMTs

“…Active retrodirective structures give a new perspective for applications, such as RFID, radio communications, and radar systems, providing better and cheaper solutions for new radio systems [4][5][6][7][8][9][10].…”

Microwave phase conjugation using antenna arrays

“…To address the problem of amplified leakage signals coming out from our phase-conjugate elements, a two-stage mixing technique has been proposed [11]. To understand how it works, let us consider that the sampled incident signal has a phase factor of .…”

“…2. It was first proposed in the 1960's, but due to the lack of modern semiconductor and photonic technologies, researchers did not have practical ways to realize this concept [10], [11].…”

Active Circular Retro-Directive Array

“…Wave propagation physics shows that wave-front phase conjugation (PC) produces retro-directivity [1]. Examples in the microwave frequency range for repeater and wireless communications are given in [2], [3]. A passive retro-directive array was published by Van Atta [4], its application was limited to linear or planar arrays.…”