Local oscillator for millimeter-wave receivers

A structure for InP TED local oscillator well stabilized by high Q quasi-optical open resonator at D band (110-150 GHz) frequency is presented. The structure consists of three cavity system. The output power of more than 2.5 mW at 2^nd harmonic is achieved from the oscillator. The maximum efficiency of the oscillator is found to be 6% whereas the average efficiency is 4.1% The tunability of the oscillator over more than 10 GHz is also developed. The Q value of the open resonator is also measured and is found to be of the order of 10⁵.