Airborne Data Link Transmitter Module Designed To Achieve

A transmitter used in airborne data link system is presented in this paper.IF signal gets converted up to L band in the module.The module has compact size,high reliability,high frequency-agile rate,low spurs and low phase noise.In this thesis,the design approach and working principle of the transmitter has been analyzed.PLL,DDS,FPGA are discussed in detail,PLL and DDS frequency synthesizer are combined to assure high performance:broad bandwidth,high frequency-agile rate,low spurs and low phase noise,and the integrated module is designed and produced,the size is 136×130×18 mm.The frequency range of the output signal is 940MHz～1240 MHz,and the step is 1MHz.The output power is 13 dBm,and the harmonics is less than 40 dBc.The phase noise of the output signal is -85dBc/Hz@100Hz,-95dBc/Hz@1kHz,-101dBc/Hz@10kHz,-108 dBC/Hz@ 100kHz, and the spur is less than 60dBc.The frequency hopping rate is less than 2us.The main contents are described as follows:Chapter one,the situation and development trend of the data link system is presented and the techniques of frequency synthesizers are presented.Chapter two,the system composition and the general scheme are investigated in detail,and the system principle is analyzed.The main parts are discussed,including switcher,filter,up-converter,DDS and PLL frequency synthesizers, etc.Chapter three,PLL frequency synthesizers are discussed,including the principle of PLL and its applications in this paper.Chapter four,DDS agile frequency synthesizers are discussed.including the principle of DDS,its structure,characteristic and development trend,and its application in this paper.Chapter five,FPGA device which used to control the time sequence and logic is presented,including the characteristic of FPGA and its application in this paper.Chapter six,the design and implementation of the module are discussed,including the main circuit design,EMC design,the implementation and test of the module.Chapter seven is the conclusion.