Radioengineering (Dec 2018)
Wideband Time Reversal of Microwave Signals Based on Phase Conjugating
Abstract
A phase conjugating network to realize wideband time reversal of microwave signals is studied in this paper. After discussions on the operation principle of the reversed signal in the time and frequency domains, a prototype network based on phase-conjugating mixing is developed. A demonstrator is designed and fabricated, and two examinations are carried out to confirm the presented method. For a fixed LO signal, a chirp RF signal with 40-MHz bandwidth can be phase-conjugated mixing, thus time reversed effectively. To widen the operation bandwidth, a method named dynamically synchronous phase conjugating is proposed; this enables a microwave signal to be dynamically reversed by synchronously varying the LO frequency along with the RF frequency, thus achieving the phase-conjugating dynamically in a wide frequency band. The simulation and experiment results of a wideband microwave signal, ranging from 5.4 to 6.25 GHz under a measured conversion loss of ≤ 10 dB, verify our studies.
