A linearized tuning varactor for voltage controlled oscillator

IEICE Electronics Express

Xiaojuan Xia¹  Xincun Ji¹  Shipu Gu¹  Yufeng Guo¹ 

[1] Nanjing University of Posts and Telecommunications

关键词: varactor;    voltage controlled oscillator;    linearized tuning gain;   

DOI  :  10.1587/elex.14.20170730

学科分类：电子、光学、磁材料

来源: Denshi Jouhou Tsuushin Gakkai

【 摘 要 】

A linearized tuning varactor for the voltage controlled oscillator (VCO) is proposed in this paper. The capacitance-voltage (C-V) curve is linearized by combining an accumulation MOSFET (AMOS) and PMOS in parallel to form the varactor. Two ring voltage controlled oscillators (ring VCOs) are fabricated and measured with a standard 65-nm CMOS process. They are both identical except for the varactor. The first VCO uses the proposed varactor, and the second one is tuned by a conventional AMOS-only varactor for reference. The ring VCO with the proposed varactor operates from 500.5 to 807.6 MHz, and the VCO gain (KVCO) varies from 183 to 284 MHz/V. Comparing the reference VCO with the AMOS-only varactor, the measured KVCO variability is reduced by 82%. The phase noise is between −89 dBc/Hz and −92 dBc/Hz at 1 MHz offset while dissipating 0.8 mA from a 1.2-V supply.

【 授权许可】

CC BY