Multi-band Bandpass Filter And Its Application In Antenna Design

With the continuous research of the fifth generation(5G)mobile communication technology and the release of some new wireless communication standards,spectrum resources are becoming more and more scarce.Therefore,the multi-standard communication technology has become a hotspot in related research area.Filters and antennas as wireless communication passive devices and also play extremely important roles in multi-standard communication systems,so the performance and size of filters and antennas may have deep effects on the transmission quality of multi-srandard communication.With the increase of operating-band number,the size and performance of the filter and the antenna will deteriorate,which is cast shadows on the for the miniaturization of passive devices or the high-quality transmission of wireless communications.In this paper,the multi-band filter and its application in the design of dual-band antenna are studied.The research goal is to design a modified type of structure and the use of new technologies to improve performance of multi-band filter and multi-frequency antenna which will be instructive for potential design of multifunctional components in future communication systems.The main contents are as follows:1.The stub-loaded resonator(SLR)was analyzed and the formula corresponding to the odd-and even-mode resonant frequencies are given.Then,a miniaturized source-load inductive coupling is proposed,analyzed,and applied to the design of dual-band and quad-band filters.Input/output cross-coupling is introduced,which will benefit the selectivity and the miniaturization of quad-band filter.Finally,the filter has been processed and tested,which demonstrates the correctness of the design ideas.2.A new stub-loaded ring resonator(SLRR)was designed and its equivalent circuit is analyzed by using the odd-and even-mode analysis method to derive the odd-and even-mode resonance condition.Then,the odd-and even-mode resonant frequency will be determined,eight resonant modes are extracted.Meanwhile,two open-circuited stepped impedance stubs are folded inward to introduce stub-to-stub coupling.And then become a ten-mode structure.After that,a single resonator was parallel coupled to achieve the filter characteristics of the quint-band.Finally,the filter has been processed and tested,which proves that the proposed quint-band filter based on a single ten-mode SLRR has the advantages of miniaturization and band-to-band isolation.3.A full-wavelength ring resonator based on substrate integrated coaxial line(SICL)technology is proposed,with which a diplexer based on SICL technology is designed.After that,two linear slot array antennas operating at different frequencies based on the SICL technology and the Chebyshev power-division network are designed and simulated.Two sub-arrays interdigitally share the aperture on a double-layer substrate.The miniaturization,good radiation performance and filtering characteristics of the proposed dual-band slot array antenna can be achieved.Finally,the dual-band antenna has been fabricated with multi-layer PCB process and tested,which proves the correctness of the design idea.