24 GHz InGaP-GaAs HBT push-push VCO with broadband tuning range

Paper in proceeding, 2009

A push-push topology MMIC microstrip VCO with output taken from tank common-node has been designed and implemented in an InGaP/GaAs HBT process. It provides an output at second harmonic at 24 GHz and differential output for PLL at 12 GHz. The oscillator shows an excellent phase noise performances of -93 dBc/Hz at the fundamental frequency and -89 dBc/Hz at the second harmonic output at 100 kHz offset from the carrier. Different doping profile varactors are investigated and VCO tuning range larger than 35% is obtained.