5.4 GHz −127 dBc∕Hz at 1 MHz GaInP∕GaAs HBT quadrature VCO using stacked transformers

Abstract

The first fully integrated GaInP/GaAs heterojunction bipolar transistor (HBT) quadrature voltage controlled oscillator (VCO) using the stacked-transformer LC tank is demonstrated at 5.43–5.31 GHz with low-phase-noise performance. The stacked-transformers are formed by two interconnect metal layers and possess good electrical properties at high frequencies because of the semi-insulating GaAs substrate. The quadrature VCO at 5.38 GHz has phase noise of −127.4 dBc/Hz at 1 MHz offset frequency, output power of −4 dBm and a figure of merit (FOM) −191 dBc/Hz.