Low‐phase noise VCO using output matching network based on novel harmonic control circuit

Abstract

AbstractIn this article, a novel voltage‐controlled oscillator (VCO) using the output matching network based on the novel harmonic control circuit is presented for reducing the phase noise without the reduction of the frequency tuning range. The phase noise suppression is achieved by the harmonic control circuit having the short impedances for the second‐ and third‐harmonic components. The high‐Q resonator has been used for reducing the phase noise but has the problem that the frequency tuning range has been also reduced by the increase of the Q value of the resonator. However, the frequency tuning range of the proposed VCO has not been reduced because the phase noise has been reduced without the high‐Q resonator. The microstrip square open loop multiple split ring resonator has been used with the proposed harmonic control circuit for better phase noise property. The phase noise of this VCO has been −127.5 to −126.33 dBc/Hz @ 100 kHz in the tuning range, 5.744–5.865 GHz. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1838–1842, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24510