A compact 43-GHz monolithic differential VCO in 0.5-μm InP DHBT technology

A compact monolithic integrated differential voltage controlled oscillator (VCO) using 0.5-μm emitter width InP/InGaAs double-heterostructure bipolar transistors with a total chip size of 0.42 mm × 0.46 mm is realized by using cross-coupled configuration for extremely high frequency satellite communications system applications. The device performance of F_max greater than 320 GHz at a current density of 5 mA/μm² and 5-V BVceo allows us to achieve a low phase noise 42.5-GHz fundamental VCO with -0.67-dBm output power. The VCO exhibits the phase noise of -106.8 dBc/Hz at 1-MHz offset and -122.3 dBc/Hz at 10-MHz offset from the carrier frequency.