High-speed High-precision Radar If Digital Technology Research

In this paper, we summarize the basic principles of the IF (Intermediate Frequency) digital technology and detail the project and realization of the IF digital system.IF receiver plays one of the most important parts in the modern radar system, to realize the whole digitization of the radar receiver has become an important matter in the researching and manufacturing of the high precision radar. With the fast development of the Software Radio technology, whether in the communication system or in the radar system, the IF digital receiver is expected to be designed based on the Software Radio technology in order to define the function of the hardware by the software, which can improve the facility and the reliability of the system greatly. The main objective of this paper is to research the IF technology thoroughly and to discuss the project of the realization so as to found the basis for the development of the IF digital receiver.The primary works in this paper are presented as follows:1. To complete the project demonstration and simulation of the system.2. To understand the function of the high speed and high precision analog-to-digital converter (AD6644), to complete design of the circuit and the hard-ware realization of the sampling cell, to detail the testing method and the testing results of the high ADC's main dynamic features.3. To understand the structure and the function of the programmable digital down-converter (AD6620) deeply, to complete the design of the circuit and the hardware realization of the IF digital orthogonal demodulation cell, to introduce the testing method and the testing results of the amplitude consistence error and phase orthogonality error of the output demodulation signals.