Varactor-tuned planar W-band oscillator

A planar, hybrid, integrated VCO (voltage-controlled oscillator) for the W-band has been fabricated on a high-resistivity (10000 Omega cm) silicon substrate. For this purpose an oscillator circuit for fixed-frequency CW (continuous wave) operation has been extended to obtain frequency variation by voltage control. Frequency variation is obtained by coupling a radial line sector to a disk resonator using a varactor diode. An Si quasi-read double-drift IMPATT diode is used as the active device. A hyperabrupt doping profile is used in the varactor diode. The chip size is 6*4.5 mm/sup 2/. A tuning range of 380 MHz around 80.2 GHz with an output power of 18 mW is obtained.<>