Research On The Key Technology Of Multi-channel Down Conversion Module

With the continuous development of phased array technology in recent years,phased array radar antenna system has a wider application range and a deeper application degree.As the core component of phased array radar antenna system,multi-channel down conversion module has been paid more and more attention.It is of great practical significance and engineering value to study multi-channel,high efficiency and miniaturization down conversion module.Based on the theory of microwave devices such as microstrip power divider,microstrip filter and hybrid microwave integrated circuit technology,a Ku band 12channel down conversion module is developed by using microwave multi-layer PCB technology and micro assembly technology.The module is mainly composed of power divider,amplifier,mixer,filter and other devices,with numerical control attenuation,low noise amplification,RF filtering,secondary change Frequency,IF filtering,IF amplification and other functions.In this paper,the design of Ku band 12 channel down conversion module is discussed in detail according to the technical specifications of the project.Based on ADS simulation software,the feasibility of index allocation and link budget is analyzed.Based on the basic theory of microstrip power divider and microstrip filter,four passive structures are designed by HFSS electromagnetic software:two one twelve microstrip Wilkinson power divider,hairpin microstrip band-pass filter and interdigital microstrip band-pass filter in different frequency bands;based on multi-layer Microwave PCB technology and micro assembly technology,the interconnection structure of components is modeled,simulated and optimized.Based on the condition of component heat dissipation,several chips with serious heat generation are analyzed,and the modules are modeled,simulated and optimized by using the software of Flotherm to improve the reliability of the modules;based on the theory of electromagnetic compatibility and the technology of microwave hybrid integrated circuit,the Ku band12 channel down conversion module is designed,through secondary frequency conversion,the reception gain of each channel is greater than 72dB,the image rejection is greater than 55dBc,the isolation between channels is greater than 47dB,the noise coefficient is less than 5dB,and the size is 160×180×18mm~3.All indexes meet the requirements of the project.