Retro-directive array with beam steering capability, made by coupled, self-oscillating mixers

A novel, phase-conjugator array for active, retro-directive operation has been made by use of three dual-gate, self-oscillating mixers (SOM's), mutually locked by use of 6 dB hybrid couplers. The coupling network incorporates the load of the oscillators. Reduced LO penetration has been achieved at the RF and IF and ports by trapping the LO signal within the do bias lines of each SOM. Injection of two external signals at the LO frequency, each at a marginal SOM, with phase difference Delta Phi between them, allows for retransmission at angles other than the angle of arrival of the incident signal. Measured results are presented for a retro-directive array designed for nominal operation at 900 MHz. (c) 2007 Wiley Periodicals, Inc.