The Research Of Microwave Broadband Frequency Conversion Module

Transceiver component act as the part before the signal processing,and after the radar receive system,which is located in the middle of the whole system.Due to the different performance requirements in radar system,the complexity of the actual composition and the specific circuit of the transceiver components are not the same,the basic principles of composition is similar,mainly conclude by the transformation circuit,switch filters and the intermediate circuit,etc,As the miniaturization and diversification of the radar system,the frequency conversion component also develops towards modularity,miniaturization and high reliability.Wide-band microwave transceiver used in electronic countermeasures,missile guidance system,and radar system,is the core component of these systems.It implements the selection of wide-band signal and the transformation of the frequency.The transceiver component directly influences the whole performance of the receive system,possessing both good application prospect and difficulties of wide-band system.Wide-band anti-jamming ability,amplitude-phase consistence,miniaturization filters,spur rejection and miniaturization physical designs are both the main and the key of the researches,which possesses innovative and scientific.In this paper,a 6-18 GHz microwave broadband frequency conversion component is studied,which has dual channel reception and calibration function.According to the functional requirements and technical indicators,first of all,based on the features of the broadband microwave receiver and the key indicators of broadband receiver scheme design is studied when the need to pay attention to detail and difficulties,to develop the implementation plan: receive channels using superheterodyne three times frequency conversion scheme,the component receives 8-channel 6-18 GHz signals,calculated by the switching network to be a double-channel signal.One channel signal outputs as a wide-band high intermediate frequency signal through twice down-conversation.The other channel signal outputs as a narrow-band low intermediate frequency signal through three times down-conversation and narrow-band filter;The realization of the calibration function is to adjust the calibration signal of the two 6-18 GHz to the receiving channel for the system to be calibrated after switching.Component total diagram split into four functional units,each unit is designed to separate functional modules: a switching network module,two high frequency modules,and an intermediate frequency module,each module are designed with independent power supply and control unit,convenient adjustment test alone.Then,the functional modules are designed,produced,debugged and tested separately,and the modules that meet the requirements are obtained.Final assembly and adjustment will be four functional modules,stray for debugging process control and the adjustment of the gain flatness of meticulous analysis,by changing the cavity structure and improve the matching of the filter,respectively,to solve the problem of stray and gain flatness problem.Finally,the microwave broadband frequency conversion module was developed.After testing,the component indexes meet the technical agreement requirements,and the gain flatness is less than 4dB.The mirror rejection is greater than 65dB;Phase consistency is not more than ±10 °;spur rejection is greater than 55 dB.The component is given to the user to load the whole machine for testing.All technical indexes and function parameters can meet the requirements of the whole machine,and can be used in the system equipment.