Design And Implementation Of The Communication Signal In The Electromagnetic Environment Simulator Phase-locked Frequency Synthesizer

Aiming at the scheme of the signal electromagnetic environment simulator of the wireless communication system,the mission of this project is to design and realize twenty-four frequency synthesizers,which must meet high expectation for the phase noise characteristic and the spurious repression characteristic of the output clock signal. These frequency synthesizers provide the moving of the basic signal generating modules to radio frequency with stable inspiring source. Phase locked loop technique offers a way to resolve this problem.On basic of researching the principle of phase locked loop,this article analyzes the output signal whose noise characteristics depend on the each part of PLL,and designs a scheme to realize the frequency synthesizers using the high performance chips with integrated prescalers and phase detectors. The visualized circuit structure is given in this paper. It is sticking point for optimizing the performance of PLL to confirm the parameter of VCO(voltage controlled oscillator) and properly design the loop filter. After debugging the hardware circuits and measuring the output signal,this paper discusses the measures used in improving the performance of the system from two aspects of theory analysis and engineering practice.