Implicit common-mode resonance by parasitic capacitances in LC oscillators for Ka-band satellite receiver

Parasitic capacitances in high frequency have a significant role in examining the inductor-capacitor tank oscillators (LC oscillators) output signal quality. Here, the authors proposed a new idea for Ka-band satellite receiver oscillator, which considers these parasitic elements, in order to maintain a specific precise frequency where there is no need for a broadband frequency range. By using tuned parasitic elements in differential LC oscillator to resonate the circuit's common mode at twice the oscillation frequency, a better phase noise performance and higher oscillator FOM can be achieved. The developed methodology is employed to design and fabricate an oscillator in 0.25 µm AlGaAs/InGaAs pseudomorphic high-electron-mobility transistors process for 19.25 GHz oscillations.