38 GHz low phase noise CPW monolithic VCOs implemented in manufacturable AlInAs/InGaAs HBT IC technology

We have demonstrated a 38 GHz voltage controlled oscillator (VCO) with an integrated buffer amplifier in AlInAs/InGaAs HBT technology. Coplanar waveguide (CPW) circuit designs has been employed for the development of the InP HBT MMIC VCOs to reduce chip cost and make them flip chip compatible. The VCO was realized in a high yield optical lithography triple mesa HBT process. This VCO delivers a typical output power of 10 dBm at a center frequency of 38.4 GHz with a tuning range of up to 850 MHz. The measured phase noise shows -82 dBc/Hz at 100 khz offset and -1.08 dBc/Hz at 1 MHz offset. Uniformity and reproducibility were also demonstrated. Circuit performance was relatively insensitive to process variation indicating a highly robust and manufacturable circuit design and process.