Technique Of Broadband DBF And Digital Channelization

Radar-reconnaissance uses the reconnaissance equipments to detect, intercept and measure the electromagnetic radiation characteristics and technical parameters of the enemy radar signals to provide the correct information for radar interference and anti-radiation attack. As the environment is unknown for the radar reconnaissance receiver, therefore, how to measure intercepted radar signals'parameters accurately is the the most important task for radar reconnaissance receiver. However, with the increasing density of electronic warfare signal and the increasing complexity of its forms, the measuring methods used in traditional analog radar reconnaissance receiver can't meet the actual demand. With the rapid development of large-scale integrated circuits, how to apply digital technology to radar reconnaissance receiver will be the future trend.This article applies the current hot concept of digital-channelization and broadband DBF(digital beam forming)technology to the radar reconnaissance receiver to measure the intercepted signals'parameters. First, the article discusses the basic principles and algorithms of digital-channelization, gives the principle of the digital-channelization based on STFT(Short Time Fourier Transform), and through the simulation, verifies that this method can measure the time and frequency domain parameters accurately in the case of a given SNR. Then, the article discusses the methods that commonly used to measure the signal's angel of arrving (AOA)in radar reconnaissance receivers, focusing on the DBF principles based on spacial FFT in the model of equidistant linear arries, and the final simulation shows that the method can not only deal with several signals'arriving angel at the same time, but also have a high accuracy of AOA-measuring.