An active self-steering array using self-oscillating mixers

A retrodirective array using self-oscillating mixers (SOMs) is presented. SOMs allow for easier implementation of larger two-dimensional arrays by eliminating the complex local-oscillator (LO) feed structure. A four-element linear retrodirective array using SOMs is demonstrated at a LO frequency of 8.87 GHz. Each element is successfully phased locked at the LO frequency while 33 dB of isolation between adjacent elements is measured at the RF frequency. The LO power generated by a single SOM element at the fundamental frequency is +3 dBm. Retrodirectivity is successfully observed for scattering angles of -30/spl deg/, 0/spl deg/, and +15/spl deg/.