Current reused Colpitts VCO and frequency divider with quadrature outputs

IEICE Electronics Express

Xincun Ji¹  Longxing Shi¹  Jianhui Wu¹  Fuqing Huang¹ 

[1] National ASIC Center, Southeast University

关键词: CMOS;    current reuse;    Colpitts VCO;    quadrature output;    Miller effect neutralization;   

DOI  :  10.1587/elex.8.239

学科分类：电子、光学、磁材料

来源: Denshi Jouhou Tsuushin Gakkai

【 摘 要 】

References(8)A low power current reused Colpitts VCO and divide-by-two circuit is proposed in 0.18µm CMOS technology. The divider is stacked on top of a common drain gm-boosted differential Colpitts VCO to share DC current. A capacitance neutralization technique is used to compensate the miller effect of the parasitic gate-drain capacitance Cgd in the VCO, and improves the generated negative resistance and phase noise performance. The Colpitts VCO works at 4.293-4.513GHz, and can provide 2.147-2.257GHz quadrature outputs through the stacked divide-by-two circuit. The VCO circuit exclude the output buffer consumes 2.8mA at 1.8V supply voltage. The measured phase noise is -109dBc/Hz at 1MHz offset frequency when the VCO output is 4.513GHz.

【 授权许可】

Unknown