A V-band low-phase-noise CMOS oscillator using a micromachined cavity

This paper presents a low-phase-noise CMOS oscillator integrated on a thin-film substrate with flip-chip interconnection. The cavity serves as a parallel-feedback element, which is fabricated using micromachining technique and is applied to the newly developed current probe scheme to reduce the coupling loss between a cavity and external circuits. The cavity was designed to have a coupling of 6 dB at a resonant frequency of 56 GHz. CMOS LNA using 0.13 mum 1P8M CMOS technology was used as a gain block to generate negative resistance. The developed CMOS oscillator has a large output power of -3.7 dBm and a low phase noise of -106 dBc/Hz at 1 MHz offset with an oscillation frequency of 55.77 GHz.