A complementary cross‐coupled quadrature VCO using ring‐inductor coupling method

Abstract

A high‐performance quadrature voltage‐controlled oscillator (QVCO) with ring inductor is studied. The QVCO uses a closed‐loop ring inductor and is composed of two complementary negative transconductance cells to replenish the energy loss due to the resistive LC resonator and is implemented in a standard TSMC 90 nm 1P9M CMOS technology. This QVCO operates between 7.05 and 8.15 GHz. The measured phase noise of the VCO operating at 8.15 GHz is −119.98 dBc/Hz at 1‐MHz offset while the QVCO draws 4.2 mA and 3.57 mW consumption from a supply voltage of 0.85 V. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:839–842, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26714

A class‐C quadrature VCO using the varactor coupling technique

“…The most popular parallel coupling QVCOs use MOSFETs or parasitic junction transistors in MOSFETs as the coupling devices which can reduce phase error but power consumption will be increased. On the other hand, coupling with passive devices will introduce less noise source than parallel coupling or lead to decreased voltage head room than top/bottom series coupling. In the previous Class‐C QVCOs , active MOSFETs are used as the coupling devices.…”