Design and implementation of a 94/188 GHz dual‐band VCO with gain‐enhanced frequency doubler IN 90 nm CMOS

Abstract

ABSTRACTIn this work, a 94/188 GHz push–push voltage‐controlled oscillator (VCO) using gain‐enhanced frequency doubler is demonstrated in a 90 nm CMOS process. Compared with the traditional push–push architecture, the proposed one can significantly increase the second‐harmonic output signal due to the inductive series‐peaking gain‐enhancement of the full‐wave‐rectifier‐based frequency doubler. In addition, low power dissipation is achieved because the bias current of the frequency doubler is reused by the cross‐coupled transistors of the VCO. The VCO draws 12 mA current from a 1 V power supply, i.e. it only consumes 12 mW. At the fundamental port, the VCO achieves a tuning range of 92.6∼95 GHz and a low phase‐noise of −88.2 dBc/Hz at 1 MHz offset from the center frequency. The corresponding FOM is −177 dBc/Hz. At the push–push port, the VCO achieves a tuning range of 185.2∼190 GHz and a low phase‐noise of −82.5 dBc/Hz at 1 MHz offset from the center frequency. The corresponding FOM is −177.3 dBc/Hz. To the authors’ knowledge, the phase noise and FOM performances of the VCO are one of the best results ever reported for a W‐band or G‐band CMOS VCO. The circuit occupies a small chip area of 0.58 × 0.61 mm2, i.e. 0.35 mm2, excluding the test pads. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:675–681, 2017