Research And Implementation Of Filter And Filtering Antenna Based On Planar Coupling Structure

In the wake of the continuous development of wireless communication technologies,wireless communication system always presents new challenges to antennas.As an important part of transmitting and receiving signals,the antenna also plays an indispensable role in the wireless communication system.With the unceasing improvement of the integration of radio frequency circuits,antennas integrated with multiple functions have been studied extensively.For the past few years,antennas with a filtering function have been researched and designed by scientists domestic and overseas.This kind of antenna is also known as the filtering antenna.The filtering antenna could suppress the clutter signal in the radio signal to advance the transmission quality of the signal.The wireless communication system is developing toward multi-frequency and broadband,thus filtering antennas with broadband filtering characteristics and dual-band filtering characteristics have become a hot research topic.The filtering antenna designed by cascading the filtering feed network and the antenna does not need additional matching circuits,reducing the complexity of the antenna design.Given the above research background,based on the broadband patch antenna combining with the broadband and dual-frequency filtering feed network,a broadband filtering antenna and a dual-band filtering antenna are designed.The main aspects of the research included in this paper are as follows:1.The design principle and method of broadband patch antenna are studied in this paper.The working characteristics of the broadband patch antenna are analyzed,and the effects of different physical parameters on the performance of the antenna are summarized on this basis.2.A broadband filter and a dual-band filter based on plane coupling structure are studied and designed as the filtering feed networks of the filtering antennas.The ideal models and working principles of two kinds of filtering feed networks are analyzed.Finally,a broadband filter provides a fractional bandwidth of 43.9%from 2.35 to 3.67 GHz,and a dual-band filter covers 2.39-2.65 GHz in the lower band and 4.67-4.83 GHz in the upper band are designed.3.A broadband filtering antenna and a dual-band filtering antenna are designed.By cascading the patch antenna and the filters,both two kinds of filtering antennas can achieve good filtering characteristics and impedance matching characteristics in the working frequency band.The broadband filtering antenna also has good wideband performance with a fractional bandwidth of 43.0%from 2.34 to 3.62 GHz.The dual-band filtering antenna covers 2.42-2.63 GHz in the lower band and 4.69-4.78 GHz in the upper band,also has good impedance matching and frequency selection characteristics.