A 60-GHz-band subharmonically injection locked VCO MMIC operating over wide temperature range

A 60-GHz-band subharmonically injection locked VCO MMIC is developed for a local signal source. The VCO outputs a 2nd harmonic of an oscillating frequency, using a 2nd subharmonic as an injection signal to obtain a high output power and a wide locking range. The overall frequency multiplication factor is 4. Besides, to suppress an oscillating frequency fluctuation against an ambient temperature change, a simple temperature-compensation bias circuit is connected to a varactor diode. It is tested mounting on an LTCC package by a flip-chip technique. A locking range of 760 MHz and an output power of 1 dBm are obtained at the injection power of 2 dBm. For a temperature range from 0/spl deg/C to 80/spl deg/C, a locking range reaches to 450 MHz due to the temperature-compensation bias circuit.