Abstract
A wideband 60 GHz VCO with linear tuning range is proposed in this paper. The transformer-based differential tuning scheme is proposed for the fine frequency tuning, and the varactor pairs are used for the coarse frequency tuning. The VCO demonstrated 22.2 % tuning range from 56.43 to 69.79 GHz. By using the differentially tuned scheme, the proposed VCO has a linear tuning range, which can be used in wide band frequency synthesizer where a constant loop gain is desired.