A Ka-band offset phase-locked single-tuning VCO with an automatic loop bandwidth calibration

A Ka-band offset phase-locked single-tuning voltage-controlled oscillator (VCO) module with an automatic loop bandwidth (LBW) calibration is designed, fabricated and measured. In this work, the wide tuning range is realized by automatic loop filter selection through self-calibration circuitry. The proposed calibration technique and adaptive LBW theory are used to overcome problems caused by large variation of the VCO tuning sensitivity and to improve the in-band phase noise of phase-locked oscillator (PLO) by at least 17 dB. The experimental results show that the 33.55 GHz PLO phase noise of -97 dBc/Hz is achieved at offset frequency of 200 kHz.