25-42 GHz GaAs heterojunction bipolar transistor low phase noise push-push VCOs

Two push-push thin-film VCOs (voltage-controlled oscillators) utilizing GaAs-AlGaAs heterojunction bipolar transistors that cover the 25-42 GHz frequency range are presented. Key features of the designs are: greater than 33% continuous tuning bandwidth, SSB phase noise less than -70 dBc/Hz at 100 kHz offset, and better than -90-dBc fundamental spur suppression. Over 10 GHz of tunability has been achieved using this design. It is suggested that this wide tuning range in a single oscillator allows significant size, weight, and power improvements in wideband communication systems.<>