中文摘要：

提出了一种提高混频器线性度的方法：采用交叉差分的结构取代原有的混频器结构．改进后，输出信号的三次谐波会被消除，混频器的三阶截止点也得到改善．混频器工作电压1．8V，射频信号5GHz，电路采用0．18μm CMOS工艺，使用Agilent公司的先进设计系统ADS（advanced design system）对电路进行仿真设计．仿真结果表明，经过改善后，混频器IP3提高3．5dB（线性度提高），转换增益提高4．8dB．

英文摘要：

A new technique is presented to improve the linearity of Gilbert mixer firstly. The main idea is to replace the former mixer structure with a cross-connected differential one. When one specific design condition is fulfilled,the third- order harmonic of the output signal is Canceled, improving the third-order intercept point of the mixer. The suppling voltage is 1.8V, and a RF signal is 5GHz.Based on 0.18μm CMOS process, the mixer is designed and simulated with Agilent ADS （Advanced Design System）.The simulation results show that the IP3 is improved by 3.5dB, and the conversion gain is improved by 4.8dB after improving the structure.