Optical Beam Control of Millimeter Wave Phased Array Antennas for Communications

Large aperture phased array antennas are designed with fiber-optic distribution networks to provide phase and frequency reference signals, control signals for beam steering and shaping, and data/frequency hopping signals to MMIC active T/R modules. The experimental results of a FO communication network at millimeter wave frequency of 38GHz (Ka-band) are presented. The results of 500MHz-1GHz FO link characteristics such as frequency response flatness, harmonics, and the third order intermodulation distortion are presented. Results of stabilization of a 38GHz IMPATT oscillator using indirect optical injection locking is also discussed. A locking range of 132MHz using 45dB amplification gain is demonstrated. The overall system FM noise degradation is measured to be 16dB. The communication link is established by up-conversion of the data link with the stabilized LO. Results of a true time delay phase shifter using a novel fiber striching technique is presented. A phase shift as high as 20° at 10GHz is achieved using the expansion properties of a piezo-electric ring by applying dc voltage.