A millimeter-wave reflection-type dual-frequency VCO MMIC with a coupled line

This paper presents a millimeter-wave dual-frequency voltage controlled oscillator (VCO), which enables to provide the fundamental and the second harmonic signals from its different ports without frequency multiplier and power divider. In order to provide the fundamental signals, a coupled line is applied instead of a transmission line between the transistor and the resonator in the conventional reflection-type second harmonic VCO. A coupling factor of the coupled line is the design parameter to decide the fundamental and the second harmonic output power, and phase noise. The fabricated 36 and 72 GHz-band dual-frequency VCO MMIC employing InGaP/GaAs HBT process exhibits the output power of -2.9 to -1.0 dBm at 36 GHz-band, and -10.6 to -10.0 dBm at 72 GHz-band, and the phase noise of -108 dBc/Hz at 1 MHz offset from the carrier at 36 GHz-band.