Thermal reliability of VCO using InGaP/GaAs HBTs

Degradations of InGaP/GaAs heterojunction bipolar transistor (HBT) collector current and base current subjected to cumulative long-term junction temperature stress are examined experimentally. The aged SPICE model parameters as a function of stress time are extracted from the measurement data. The VCO phase noise, tuning range, and output amplitude are studied in circuit simulation. The phase noise increases, tuning range and output amplitude decrease with increasing junction temperature.

► In this study we examine experimentally HBT’s currents subjected to long-term stress.
► The aged SPICE parameters versus stress time are extracted from measurement.
► We then study the VCO’s phase noise and tuning range in circuit simulation.
► We find that phase noise increases and tuning range decrease with junction temperature.