A new high-performance OPA based VCO for microwave applications

This paper describes a novel operational amplifier (OPA) voltage-controlled oscillator (VCO) for microwave applications. The VCO circuit is based on a wideband OPA unity gain buffer and can be used in frequency range exceeding the unity gain bandwidth. The mathematical model of the proposed VCO is developed. The designed VCO uses an ultra low noise wideband OPA LMH6624 and covers the frequency band between 1.955 GHz and 2.673 GHz, exhibits a maximum in-band phase noise of - 154.2 dBc/Hz at 1 MHz offset from carrier frequency. Power consumption of the VCO core is 57 mW from a ± 2.5 V power supply. The designed VCO achieves one of the best figure of merit value of - 204dBc/Hz at 2 - GHz band. The implemented oscillator generates low-noise signal confirming the simulation results.