Design Of Dopler VHF Omnidirectional Range Transmitter And Monitor

The civil aviation aircraft needs to receive the navigation signal from the ground navigation station at any time in the flight process,in order to determine its own position.At present,the most widely used navigation signal equipment in domestic airports is the Doppler VHF Omnidirectional Range(DVOR),It is a short range navigation device commonly used by the International Civil Aviation Organization,combines an onboard receiver with Directional beacons on the ground to provide angle information for the aircraft to guide it out of the harbor,along the flight path,and safely down the runway.After learning the background and significance of Dopler’s VHF omnidirectional range,this paper analyzes its development and current situation at home and abroad,and introduces its basic function,working principle and design requirements.Based on this,the transmitter and monitor modules of DVOR system are designed and simulated,and then verified by experiments.Transmitter Module,According to the composition structure,technical performance,working principle and design requirements of the transmitter,the transmitter module is divided into carrier generation circuit and side-band generation circuit for design.Firstly,the basic composition and functions of the two circuits are introduced,based on which the phase-locked loop RF generation mode is proposed,and the chip structure of digital phase-locked is analyzed.The balance mixer and other circuits are designed.The function of these circuits in work and the influence on the whole DVOR system are analyzed.In the end,a brief overview of the DVOR system transmitter software part of the content.According to the theoretical values,the wave-forms and level ranges of 30 Hz and side-band waves are detected.The test results strictly lock the phase difference of 90°,and the amplitude is equal,and a good composite signal is obtained.Monitor module,According to the transmitter structure,technical performance,working principle and design requirement,the two working modes of monitor are discussed,and the working mode of DVOR System Monitor is described,the design improvements were made in a digital manner and the design of the monitor parameters,Such as 9960 Hz FM sub-carrier amplitude modulation,30 Hz modulation,magnetic azimuth and Morse code identification content.The design of the software part of the DVOR system monitoring is proposed.By using the functions of the above-mentioned equipment,the DVOR system monitoring equipment is designed.System Test,measure the signal of the equipment system,simulate and demodulate the signal of the monitor equipment,and compare with the real test result,verify the feasibility.