一种双正交零中频接收机的设计和电路实现

Design and Circuit Implementation of a Biorthogonal Zero-Intermediate Frequency Receiver

零中频接收机以其低功耗和易于单片集成等优点,已经成为射频接收机发展的重要方向,但它也存在固有的缺陷,如相位偏移导致的IQ不平衡和直流漂移.双正交零中频接收机采用交叉混频的双正交结构降低IQ不平衡对相位偏移的敏感度,并采用差分放大的形式消除直流漂移问题.通过对一种双正交零中频接收机进行改进、仿真和电路实现,电路测试结果和仿真结果相符.

Zero intermediate frequency （IF） receiver has become the direction of radio frequency receiver due to its low power consumption and easy chip integration. However, it has inherent defects like DC drift and IQ imbalance caused by phase shift. Biorthogonal zero-IF receiver employs the cross-mixing biorthogo- nal structure to decrease its sensitivity to IQ imbalance caused by phase shift and utilizes differential amplification to eliminate DC drift. This paper imptoves a biorthogonalzero-IF receiver, simnlatesit and implements it by circuits. The circuit measurement resuhs coincide with the simulation results.