20GHz镜频抑制谐波混频器

镜频抑制混频器能有效地抑制镜像频率,提高雷达和通信系统的抗干扰能力。介绍了一个20 GHz二次谐波镜频抑制混频器的设计与制作,该镜频抑制混频器采用两个相同的二次谐波混频器做为两路混频单元,两路射频输入和中频输出分别用90°的功分器/合路器与两路混频器相连,本征用威尔金森功分器等幅同相输入两路混频。借助于90°的功分器,两路混频器的镜频产物在中频90°合路器的输出端口反相抵消,有用中频在90°合路器的输出端口同相叠加。利用ADS和HFSS对该混频器进行了仿真设计,并对实际电路进行了加工测试。经测试,当中频固定在400 MHz时,射频在20～21 GHz内变频损耗小于10 dB,镜频抑制大于20 dB。

20 GHz Image Rejection Harmonic Mixer

Image rejection mixer can effectively suppress image frequency and improve the ability of anti-interference in radar and communication systems.A 20 GHz 2nd harmonic image rejection mixer was designed and machined.It consists of the same two 2nd harmonic mixers,the 90° phase shifting in RF input port and IF output port respectively,and LO signal is inputted via a Wilkison power divider.By using the 90° phase shifters,the two ways of the in-phase IF signal can be enhanced,and the two ways of the anti-phase image signal can be counteracted.The mixer was simulated by ADS and HFSS.The practical circuit was tested.According to the measured results,at the IF frequency of 400 MHz,RF frequency of 20-21 GHz,the mixer achieves a convention loss better than 10 dB,and the image rejection better than 20 dB.