A New Monolithic Ka-Band Filter-Based Voltage-Controlled Oscillator Using 0.15 $\mu$ m GaAs pHEMT Technology

This letter presents a fully monolithic Ka-band filter-based voltage-controlled oscillator (VCO) with the 0.15 μm GaAs pseudomorphic high-electron-mobility transistor (pHEMT) as the active device. A three-pole combline bandpass filter is treated as a frequency stabilization element of the feedback oscillator to achieve a low phase-noise performance. The developed VCO has a frequency tuning range of 37.608-38.06 GHz, and in this frequency rage the calibrated output power is from 6.324 dBm to 10.46 dBm. The phase noise measured at 37.608 GHz is -112.31 dBc/Hz at 1 MHz offset frequency, and its corresponding figure-of-merit (FOM) is -182.7 dBc/Hz.