Advanced PON Retrodirective Array Phase Conjugate Cell for RCS Applications

A novel dual cell phase conjugate circuit is presented that when used in conjunction with dual-port microstrip patch antennas allows polarisation agility of the signal re-transmitted from a PON type retrodirective antenna array while preserving the phase conjugation properties necessary for selftracking. Up to ten distinct re-transmission modes including zero re-transmission (active radar absorber) are available from the architecture under the control of four π/2 switched phase delays. These are used to control the phase relationships between LO and the RF signals in order to achieve polarisation agility on re-transmission. A prototype array phase conjugate cell, gain 15dB, was built and the proposed concept validated by synthesising and measuring the various available phase state conditions required for polarisation agility and total re-transmitted signal cancellation. The circuit is validated for its future use in the creation of a new generation of RDA arrays which have application in advanced mobile communications and provide new methods for electronic RCS control.