A Miniaturized Design For 5G Communication Filter

With the evolution of 5G communication technology,it puts forward higher requirements for the performance and size of the device.The filter occupies an important position in the RF front end as frequency selection device and its performance directly affects the quality of the communication system.Therefore,the study of high-performance and miniaturized filters is of great significance to the development of wireless communication systems.This paper focuses on the design and research of a miniaturized band-pass filter with high out-of-band suppression applied to 5G communication systems.Through the theory of microstrip transmission line and coupled transmission line,the microstrip hairpin structure bandpass filter's principle and transmission characteristics are analyzed,and two kinds of bandpass filters are designed based on this structure.The main work of this paper includes the following aspects:(1)A new type of hairpin structure is proposed based on the traditional one.By improving the resonator and introducing a new transmission zero point to solve the problem that parasitic near passband,avoids the crosstalk between adjacent bands,and achieves good frequency selection characteristics.(2)A bandpass filter for 5G communication Sub 6GHz band is designed by using a printed circuit board process.The test results shows that the new microstrip hairpin structure bandpass filter has a center frequency of 3.8GHz,a bandwidth of 200 MHz,an insertion loss of 3d B,out-of-band suppression below-34 d B,and the size is only 24.1mm(9)16mm.(3)A bandpass filter on chip for 5G communication millimeter wave band 24.25GHz-27.5GHz is designed by the integrated passive device process based on glass substrate,using TGV technology.After analyzing and optimizing the key structural parameters of the designed bandpass filter,the results shows that it working frequency meets design requirements,the insertion loss is only 2.2d B,out-of-band suppression below-40 d B,and the size is only 6.3mm(9)4mm.In summary,this paper proposes two design schemes for bandpass filters,which are aimed at5 G communication Sub 6GHz frequency band and millimeter wave frequency band respectively.Both contents the high performance and miniaturization requirements of 5G communication systems,has some engineering practical significance to promote the development of 5G communication technology.