A Demonstration of a Voltage-Controlled Inductor in a D-Band Colpitts Third-Harmonic-Extracted Injection-Locked Oscillator

A millimeter-wave (mm-wave) voltage-controlled inductor (VCI) that is based on a series inductor-capacitor tank and that achieves large ratios of maximum to minimum inductance is proposed. For demonstration, a VCI with an inductance ratio of 4 is employed in a 22-nm CMOS silicon on insulator (SOI) Colpitts third-order-harmonic-extracted injection-locked (IL) oscillator (ILO) operating from 112.5 to 135 GHz. The ILO dc power consumption is 13 mW with a 1.2-V supply but is reduced to 5.6 mW with a 0.8-V supply when a 2-V back-gate voltage is applied. Due to the proposed VCI, the core of the mm-wave ILO occupies only 0.018 mm
²
, the tunable operating range is ≥16%, and the added phase noise (PN) (~10 dB) is close to the theoretical prediction (20log(3) dB).