Research And Design Of UWB Frequency Source Based On PLL

Frequency synthesizer is an important part of modern electronic system,its performance directly determines the performance of the entire system,known as many electronic systems "heart".With the development of modern military,defense and wireless communications industries,the frequency synthesizer's performance requirements are increasingly demanding in radar systems such as radar,guided weapons,electronic measuring instruments and mobile communications,requiring low phase noise,low noise Scattered,ultra-wideband,Czech Republic,frequency,high resolution,high frequency stability.In this paper,the frequency source output frequency range of 1.7 GHz?3.4 GHz,to achieve a single point of frequency lock function and the entire output frequency range to achieve the function of sweeping.The design of the frequency source is based on a programmable PLL and is controlled by the STM32 low frequency board to control the frequency source high frequency board.The main contents of this paper are as follows:Firstly,this paper analyzes the basic composition of the phase-locked loop,introduces the design scheme of the phase-locked frequency source,expatiates the design scheme of the phase-locked frequency source from the whole to the local to the whole,and then introduces the PLL phase Noise characteristics,spurious sources and their suppression methods,and then introduced the frequency source design and analysis process,given the frequency source to achieve the main performance indicators and to achieve the function,according to these performance indicators for the main chip selection,The use of AD company to provide the phase-locked loop simulation software for the selected chip joint simulation,theoretically verify the feasibility of the program.Secondly,the design of the hardware circuit of the frequency source and the low frequency control board is introduced.The design of the power module and the design of the loop filter are introduced.Then,the realization scheme of the software is given according to the timing diagram of the PLL chip.Finally,through the test of the frequency source,the test data are obtained,and the software and hardware are adjusted to meet the requirements of the theoretical analysis.The frequency source is used in the output frequency range,frequency step,phase noise,spurious Suppression and other performance indicators in line with project requirements.