Research And Design Of Filter Power Divider Based On Parallel Coupled Line Structure

Nowadays,the communication system is developing towards the trend of miniaturization,integration,high speed and high performance,which also promotes the miniaturization of RF microwave devices.Filters and power dividers are the two most common devices in RF circuits which is often applied to the system as a separate device in a cascaded manner.The filter power divider merge them together that can meet the performance indicators of the filter and power divider,and can also meet the needs of miniaturization.Based on the above research background,this thesis did the following research:1.This thesis designs a broadband filter power divider.The filter power divider consists of a parallel coupled line structure and a step impedance open stub.By loading a step impedance open-circuit stub resonator,two transmission zeros are introduced on both sides of the passband,which improves frequency selectivity,and finally realizes a filter power divider with broadband filtering performance.2.This thesis proposes a broadband filter power divider with good out-of-band rejection performance.The filter power divider replaces the quarter-wavelength transmission line in the traditional Wilkinson power divider by two parallel coupled line resonators,and a stepped impedance open stub resonator is loaded in the middle.The structure produces four transmission zeros,which improves frequency selectivity and out-of-band suppression capability,and finally realizes a broadband filter power splitter with better pass-band characteristics and out-of-band suppression.3.This thesis uses the multimode resonator method to design a dual-frequency filter power splitter that can work simultaneously in the WLAN and 5G bands.The dual-band filter power splitter is composed of a parallel three-wire coupling structure,two multimode resonators and a quarter-wavelength impedance converter.In the end,three transmission zeros were generated through this structure,which realized the coverage of two communication bands of WLAN and 5G.