1 Introduction [b] 1.1 Background of the Topic[/b] Software-defined radio (SDR) technology, which uses general-purpose programmable devices or digital signal processors to construct hardware platforms and defines different application functions using software, has received widespread attention in the radio field in recent years. SDR breaks through the design limitations of traditional radio stations, which are based on single-function, poorly scalable hardware. It emphasizes a new design approach that uses open, minimal hardware as a general-purpose platform and implements various radio functions using upgradeable and reconfigurable application software. All these advantages make SDR the future direction of radio technology development, and it has already made great progress in military communications and civilian applications, gaining increasingly widespread application. The closer the A/D and D/A converters of the system are to the antenna, the closer they are to the ideal SDR concept. For microwave receivers, due to current device speed limitations, it is not yet possible to directly use RF sampling SDR technology. However, using a digital receiver based on the SDR concept at intermediate frequency (IF) can still bring many of the aforementioned conveniences and flexibility in application. 1.2 Overview of IF Digital Receivers The key to SDR digital receivers is to place the A/D/A converters as close to the antenna as possible. Ideally, software-defined radio (SDR) digitization would involve direct RF sampling at the antenna's back end, with all subsequent processing implemented via software programming using digital signal processing methods. However, due to the limitations of the Nyquist sampling theorem, the data rate after high-speed A/D conversion in a broadband digital receiver must be at least twice the bandwidth. Current ADC devices are insufficient for low-pass sampling at RF; simultaneously, the requirements for subsequent digital signal processing speed are also extremely high, making it difficult to achieve with existing device capabilities. Therefore, some compromises are necessary to ensure the system retains the characteristics and advantages of SDR while maintaining its feasibility. [b][align=center]For more details, please click: Research on Digital Frequency Conversion and Adaptive Equalization Technology in Intermediate Frequency Digital Receivers[/align][/b]