A 10.3-to-11.4GHz 191.2dB FoMA Impedance Boosting Series-Resonance Oscillator Using Inverse-Coupling Transformer and Current-Compressed Transistor Achieving −144.3dBc/Hz PN at 10MHz

In this paper, an impedance boosting series-resonance oscillator using inverse-coupling transformer and current-compressed transistor is proposed to achieve the low phase noise and low power consumption. The series resonator employs an inverse-coupling transformer to enhance its input impedance while maintaining a high tank quality factor, thereby balancing power consumption and phase noise performance. By adjusting the bias voltage, the output voltage of the inverter is shaped into a pseudo-square waveform, allowing the transistors to operate without over-voltage stress. Lowering the bias voltage increases the active gain, which suppresses active device noise and reduces power consumption. The proposed series-resonance oscillator is designed and fabricated using a 40-nm CMOS process. Measurement results show a phase noise of –144.3 dBc/Hz at a 10-MHz offset and a corresponding FoM of 186.4 dBc/Hz, and a FoMA of 191.2 dBc/Hz with 10.6% frequency tuning range.