引言通信、导航、识别(CNI)综合化系统须使用具有电调谐能力的小型接收机,其工作频段为960～1215兆赫。该接收机前端电路由电调谐预选器、射频放大器、L波段调谐电压分配板及平衡混频器组成。为使该前端结构紧凑、体积小巧,适合于机载设备使用,除电调预选器采用同轴腔体结构外,其余均为带 Introduction CNI integrated systems require the use of small receivers with electrical tuning capability, operating at 960-1215 MHz. The receiver front-end circuit consists of an electrically tuned preselector, a radio frequency amplifier, an L-band tuning voltage distribution board, and a balanced mixer. In order to make the front end compact and small in size, it is suitable for the use of airborne equipment. In addition to the coaxial cavity structure used in the ESC, the rest are belts