CMOS digital controlled oscillator with embedded DiCAD resonator for 58–64GHz linear frequency tuning and low phase noise

Abstract

A digital controlled artificial dielectric (DiCAD) differential transmission line is embedded in 90 nm CMOS to digitally tune a 58-64 GHz DCO. DiCAD varies epsiv <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r,eff</sub> from 18.8 to 32.5. A shunt open stub DiCAD provides discrete capacitive tuning with 13.1deg S11 phase variation. The core oscillator is an inductively loaded differential, cross-coupled NMOS pair. Large nonlinear varactors are avoided, and the phase noise is better than -90 dBc/Hz at 1 MHz offset. Linear tuning bandwidth of 9.3% with a 61 GHz center frequency occupying 0.01 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is achieved. Power consumption is 8.52 mW with 1.2 V.