一款应用于GPS接收机的抗失配零中频混频器  

A Mis-matching Tolerant Zero-IF Mixer for GPS Application

作　　者：庄海孝[1] 马成炎[1,2] 叶甜春[1] 

机构地区：[1]中国科学院微电子研究所,北京100029 [2]杭州中科微电子有限公司,杭州310053

出　　处：《固体电子学研究与进展》2010年第4期528-533,共6页Research & Progress of SSE

基　　金：国家高技术研究发展(863)计划基金资助项目(2007AA12Z344)

摘　　要：为了解决单正交零中频混频器I/Q失配造成的影响,提高自身镜像抑制能力。基于电位混频原理采用CMOS 0.18μm工艺设计出一款工作在1.575 42GHz双正交结构的抗失调零中频混频器,通过添加四个电容构成MOSFET-C低通滤波器以及两个在低频段工作的运放构成的输出放大级,射频输入信号能够得到有效处理。测试结果表明该结构在镜像抑制能力上比传统结构改善了6dB左右,电路采用1.8V供电电压,功耗为3.6mW,1MHz频点附近的噪声系数约为17dB,1dB输入压缩点为14.6dBm。This paper presents a novel zero-IF topology mixer called the double orthogonal zero-IF to reduce the influence of image signal that is caused by imbalance of amplitude and phase of I/Q channel in receiver.The mixing is based on the modulation of MOS transistor in the triode region which renders an excellent linearity.With four extra capacitors added to the classical cross-coupled MOSFET-C low-pass filter structure,1.575 42 GHz signal can be processed while only two low-frequency op amps are required as output amplifier.Studies have shown that with the new topology the sensitivity to phase errors of orthogonal channels can be significantly decreased,and that the image-recognition ratio（IRR） against the gain mismatch characteristics is inherently superior to the conventional zero-IF scheme by^6 dB.Test results show that the circuit has a noise figure of 17 dB@1 MHz,a P1dB of 14.6 dBm.The circuit was designed and implemented in 0.18 μm CMOS process,consumes 2 mA current from 1.8 V supply voltage.

关 键 词：零中频 双正交 相位失配 幅度失配 

分 类 号：TN773[电子电信—电路与系统]