Mirror Image Sawtooth Phase Conjugator Circuit for Retrodirective Antenna Applications

Abstract

A new type of phase conjugating circuit which uses the properties of a linear sawtooth wave and an inverting sample and hold (S&H) circuit in order to produce a phase conjugated output signal is reported. Since the circuit performs phase conjugate action at a low frequency the need for circuit components operating at twice the incoming RF frequency, a requisite for all previous single mixer based circuit solutions is removed. The circuit has been experimentally verified for operation at 960 MHz. Phase conjugation errors of better than 15 , less than the 24 needed for unimpaired 4-element retrodirective array operation, were obtained from the configuration.Index Terms-Phase conjugation, phase locked loop (PLL), retrodirective antenna array.