1.5 GHz voltage controlled oscillator with 3% tuning bandwidth using a two-pole DSBAR filter

Abstract

First results on a novel power efficient voltage controlled oscillator (VCO) in the lower GHz range, featuring excellent phase noise, high frequency accuracy and stability are presented. The heart of the VCO is a novel miniature two-pole De-coupled Stacked Bulk Acoustic Resonator (DSBAR) filter recently reported. With its single 180 deg. phase transition over the 1 dB bandwidth, linear phase and maximum 1 dB insertion loss it provides stable single-mode operation over 45 MHz (≈3%) of tuning bandwidth and negligible heat dissipation when operated at incident power levels of 100 mW and higher. The 1,55 GHz laboratory VCO prototypes operate at 5V supply voltage, 50 mA supply current, 15 dBm of output power and >13% efficiency demonstrating −83 and <−180 dBc/Hz phase noise suppression at 1 KHz carrier offset and in the thermal noise region, respectively. VCO with cascaded DSBAR filters for further phase noise reduction are also demonstrated.