Design And Research Of The Miniaturized Ultra Wideband Bandpass Filter

In today's society,the wireless communication has been used more and more widely,make the spectrum resources bottleneck effect more obvious,which will seriously affect the progress of communication technology,thus forcing communication technology to move forward high frequency bands.With the improvement of the communication system requirements,the filter as the key part of the system has also put forward new requirements and requires the development of miniaturization,high performance and low cost.Therefore,the research of miniaturized ultra wideband filter in this thesis has a certain significance to the development of the communication system,the following will be studied from two aspects of miniaturized ultra wideband filter.1.Based on the traditional parallel coupled microstrip line to design a band-pass filter,the simulation result is obtained by theoretical calculation,but the traditional method to get the simulation results are not meet the requirements of design index.In this thesis,an optimization method is presented according to the optimization methods in HFSS software to scan parameters optimized get the band-pass filter can meet the requirements of indicators.2.By corroding T-shaped transmission line,we got the parallel coupled microstrip line structure,which improved the traditional parallel coupled microstrip line.In this thesis,we use the improved parallel coupled microstrip line structure to design a miniaturized ultra wideband bandpass filter.By comparing the simulated effect on the traditional filters and the improved filter,we found that the modified parallel coupled microstrip line miniaturized ultra wideband bandpass filter design are improved in terms of size and bandwidth.3.The interdigital capacitor in the composite left and right hand transmission line is improved from one layer structure to two layers.For implementing the symmetrical structure,the same right-handed materials are placed on both sides of the left hand materials,and the improved structure is designed by HFSS software to get miniaturized ultra wideband bandpass filter.By comparing the simulated effect on the traditional filters and the improved filter,the improved two-layer interdigital capacitance structure is superior to the traditional structure in terms of bandwidth to meet the ultra-wideband index.