A FPGA-based Jummer For VHF Frequency-hopping System

With the development of science and technology, military communications and Electronic Counter Measures have been constantly updated. Frequency Hopping system plays a more and more important role in the field of military communications for its prominent anti-jamming performance. In military communications, the effective counterwork anti transmitter-receiver of ultra-short waves is a focus issue nowadays and one of the difficult problems is how to generate jamming signals with evident efficiency and appropriate power.The paper produces a way of utilizing technique of digital frequency synthesis to generate jamming signals of multiple jamming modes. In this paper the principle and the structure of DDS are described .Switch between parallel and serial signals with USB interface and implementation of effective control for FPGA chip are introduced. The paper probes into a method to program FPGA with hardware language and applications of FPGA technology to the control circuit design. There are two ways to induct DDS to generate jamming signals of multiple modes, one is to utilize FPGA to induct DDS based on the instant carrier frequency in Frequency Hopping communication generated from electronic reconnaissance, so as to generate tracking jamming signals with adjustable power; the other is to generate jamming signals with adjustable modes and variable velocity such as no tracking jamming signals including single frequency, sweep-freqency and random frequency. These jamming signals are utilized to test and analyze the performance of frequency hopping and the jamming capability of multiple jamming signals anti freqency hopping transmitter receiver. Finally a summarize and the method of how to further improve the relevant technology are given.