Quadrature Hartley VCO and Injection-Locked Frequency Divider

Sheng-Lyang JANG
Chia-Wei CHANG
Sheng-Chien WU
Chien-Feng LEE
Lin-yen TSAI
Jhin-Fang HUANG

IEICE TRANSACTIONS on Electronics   Vol.E91-C    No.8    pp.1371-1374
Publication Date: 2008/08/01
Online ISSN: 1745-1353
DOI: 10.1093/ietele/e91-c.8.1371
Print ISSN: 0916-8516
Type of Manuscript: LETTER
Category: Electronic Circuits
CMOS,  Hartley oscillator,  injection locked frequency divider,  quadrature VCO,  

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Novel low phase noise quadrature voltage-controlled oscillator (QVCO) and quadrature injection locked frequency divider (QILFD) with two coupled Hartley VCOs are proposed and implemented using the standard TSMC 0.18 µm CMOS 1P6M process. The QVCO employs pMOS as the core to reduce the up-conversion of low-frequency device noise to RF phase noise. It uses super-harmonic coupling technique to couple two differential Hartley VCOs and four small-size coupling transistors to set the directivity of quadrature output phases. At the 1.7 V supply voltage, the output phase noise of the QVCO is -124 dBc/Hz at 1 MHz offset frequency from the carrier frequency of 4.12 GHz, and the figure of merit is -185 dBc/Hz. At the supply voltage of 1.7 V, the total power consumption is 13.1 mW. At the supply voltage of 1.5 V, the tuning range of the free-running QILFD is from 2.05 GHz to 2.36 GHz, about 310 MHz, and the locking range of the ILFD is from 3.99 to 5.19 GHz, about 1.20 GHz, at the injection signal power of 0 dBm.