4-GHz Low-Phase-Noise Transformer-Based Top-Series GaInP/GaAs HBT QVCO

The fully integrated GaInP/GaAs heterojunction bipolar transistor (HBT) transformer-based top-series quadrature voltage controlled oscillator (QVCO) is demonstrated at 4 GHz. The transformers on the semi-insulating GaAs substrate possess good electrical properties at high frequencies. The quadrature VCO at 4.1 GHz has phase noise of -120 dBc/Hz at 1MHz offset frequency, output power of 2 dBm and the figure of merit (FOM) -178 dBc/Hz