Analysis and Design of Magnetically Tuned W -Band Oscillators

A transformer-based magnetic tuning technique with both coarse and fine frequency tuning is proposed to enhance the frequency tuning range (FTR) and phase noise performance of
$W$
-band oscillators. Compared with our previous related works, a more detailed and thorough analysis of the magnetic tuning technique, especially the design and optimization of the proposed multicoil transformer with coarse- and fine-tuning switches, is included. Two prototypes are designed and evaluated in a 65-nm CMOS process. A proposed
$W$
-band varactor-less dual-band voltage-controlled oscillator (DB-VCO) prototype achieves an FTR of 14.3% from 95.7 to 110.5 GHz with a phase noise of −106.9 dBc/Hz at 10-MHz offset and consumes 6.2-mW power, corresponding to an FoM
_T
of −181.7 dBc/Hz. Another proposed
$W$
-band transformer-coupled quadrature VCO (TC-QVCO) prototype achieves an FTR of 11.9% from 88.8 to 100 GHz with a phase noise of −110.5 dBc/Hz at 10-MHz offset and consumes 14.5-mW power, corresponding to an FoM
_T
of −179.7 dBc/Hz. The proposed DB-VCO and TC-QVCO occupy small core areas of 0.02 and 0.022 mm
²
, respectively.