A compact resistive quadrature low noise Ka-band VCO SiGe HBT MMIC

A compact resistive I/Q low noise Ka-band voltage-controlled oscillator is reported in this paper. The oscillator consists of two emitter-coupled logic based high-frequency inverters and a voltage-to-current converter for the oscillation frequency control. The oscillator provides differential I/Q outputs for future integration with a sub-harmonic down-conversion mixer. The oscillator demonstrates a gain of 4.31 GHz/V with a phase noise of -75 dBc/MHz at 1 MHz offset over the oscillation bandwidth. The oscillator consumes between 117 to 148 mW from a 4V supply for different tuning voltages. The oscillator was designed using a high-frequency design methodology and was then optimized for a low-noise operation