Application Of DDS In A Radio Compass Test Signal Generator

A radio compass is a kind of navigational aid which is used to fix the direction by radio technology. An aircraft radio compass is an important airborne avionics. The performances of the technology play an important role in the security of airborne combat training and safety of the airplane. Therefore, the accurate testing on the performance index of aircraft radio compass is very important.Based on DDS (Direct Digital Synthesis) technology, this paper studies a new method of realization of radio compass test signal—radio compass testing signal generator module. The main tasks are as follows:Firstly, the significance of DDS technology used in developing new type of radio compass testing signal generator module is discussed. Based on the summarizing the present research states which is in-country and overseas, the main idea of the paper is put forward.Secondly, the directed theory of radio compass is studies, and the elements and application of DDS technology is discussed.According to the studies above, the signals requirements of the performances testing of radio compass are achieved. Based on these requirements, a hardware scheme is put forward. This scheme controls AD9854 and its assistant circuits with a SCM—C8051F020 to achieve three kinds of sine wave which is contented to design requirements.At last, an actual circuit of this scheme is designed and tried. As results, the output of this module is fit on the requirements of performances testing. According to the contrast of experiment results and ideal output signals, an error analysis is carried out, and the conclusion of increasing the signal precision with improving the performances of filters is achieved.