射频电路中混频器的设计

目前实现小型化以及低功耗射频电路的一种可行性方法是实现收发机射频电路的集成。在射频电路的前端,混频器是实现频谱搬移的重要器件,是十分重要的模块。设计了一种微带平衡混频器,其主要由3dB定向耦合器、匹配电路、晶体管和低通滤波器组成,滤波器用来滤除输出信号中高次谐波频率成分,从而得到需要的中频成分。然后用ADS软件进行各部分电路设计、仿真,从功能仿真图中看到输出信号的频谱中有需要的中频频率成分,这就验证了混频器频谱搬移的功能。

Design of mixer in RF circuit

A feasible method to achieve miniaturization and low power consumption RF circuit is integration of transceiver RF circuit.The mixer at the front-end of RF circuit is an important device to implement the spectrum shift.It is a very important module.A micro-strip balanced mixer composed of 3 dB directional coupler,matching circuit,transistors and low-pass filter is designed.The filter is used to filter out high-order harmonic frequency components in the output signal,thereby to obtain the required intermediate frequency components.The circuit design and simulation of each circuit were performed with the ADS software.There are the needed intermediate frequency components in the output signal frequency spectrum,which can be seen in the functional simulation diagram.It verified the spectrum shift function of the mixer.