Design And Implementation Of High Frequency Steep Decay Linear Phase Shift Filter

As a signal filtering device,the filter's performance on frequency selection makes the filter an indispensable part of the communication system.With the development and progress of technology,electronic communication systems have also put forward higher requirements for filter performance.Although crystal filters have their own advantages in various filters,such as higher quality factor,steeper transition bands,etc.,how to achieve the high requirements of modern communication systems for crystal filters.For example,how to achieve both higher amplitude and higher phase-frequency characteristics at higher frequencies and how to maintain crystal filter performance at extreme temperatures.This is what the subject needs to study.Based on this background,this paper aims at how to meet the steep attenuation(magnitude-frequency characteristics)and linear phase shift(phase-frequency characteristics)targets under high-frequency conditions.Through the research on the current situation of crystal filter design and the related theory of crystal filter design in recent years,the process of producing required filter samples for completing the project is described in detail.Through the overview of the design method of the crystal filter,according to the requirements of the filter to be realized,we choose the network synthesis method to complete the crystal filter design.By analyzing the characteristics of different filter response functions in the network synthesis method,the performance of the filters made by these three response functions is mainly analyzed for Chebyshev,Bessel response functions,and equi-ripple linear phase-shift filter functions.The ADS(Advanced Design System),an electronic design automation software from Agilent,was used to optimize parameters in the theoretical design to obtain the best parameters.According to the optimized parameters,complete the development of the filter sample.By comparing the technical indexes required by the project and the filter indicators completed in this project,the filter sample performance index designed in this paper is good and can meet the engineering requirements,providing a good performance frequency selection device for the engineering system.