A 65nm CMOS current controlled oscillator with high tuning linearity for wideband polar modulation

A highly linear oscillator is presented for wideband polar modulation. It has both varactor voltage tuning for frequency locking and temperature compensation as well as inductive current tuning for linear phase modulation. Implemented in 65nm CMOS, it achieved a gain variation less than ±2% over more than 32MHz range meeting WCDMA polar modulation requirement. At 3.8GHz and 3MHz offset, its phase noise is −136.5dBc/Hz with current consumption of 18mA from 2.1V supply.