A Wide-Tunable LC-Based Voltage-Controlled Oscillator Using a Divide-by-N Injection-Locked Frequency Divider

Shoichi HARA  Kenichi OKADA  Akira MATSUZAWA  

IEICE TRANSACTIONS on Electronics   Vol.E93-C    No.6    pp.763-769
Publication Date: 2010/06/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E93.C.763
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Analog Circuits and Related SoC Integration Technologies)
CMOS,  VCO,  divider,  inductor,  

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This paper proposes a novel wideband voltage-controlled oscillator (VCO) for multi-band transceivers. The proposed oscillator has a core VCO and a tuning-range extension circuit, which consists of an injection-locked frequency divider (ILFD) and flip flop dividers. The two-stage differential ILFD generates quadrature outputs and realizes two, three, four, and six of divide ratio with very wide output frequency range. The proposed circuit is implemented by using a 90 nm CMOS process, and the chip area is 250200 µm2. The measured result achieves continuous frequency tuning range of 9.3 MHz-to-5.7 GHz (199%) with -210 dBc/Hz of figure-of-merit (FoMT).