Research And Design Of Antenna With Filtering Response

With the continuous development of mobile communication system and the maturation of communication technology,people’s requirements for mobile devices are becoming more and more demanding.With the advent of 5G,antenna design also faces challenges.Considering that 4G and 5G signals coexist for a period of time in the future,the new generation of wireless communication equipment not only requires compact structure,small size,but also requires the equipment to support multiple working bands,so the traditional single function device has not been able to meet the design requirements.Filter antenna is to integrate the design of filter into the antenna,which can not only achieve a variety of functions,but also improve the characteristics of gain and frequency selection while reducing the size.The main research content of this paper can be divided into three aspects:1.Aiming at the fusion filtering characteristics of plane antenna across 4G/5G band,based on the study of dual-band antenna and filter design theory,a planar filter antenna working in WLAN dual-band is designed by using the bandpass characteristics generated by the third-order open-resonant ring loading branches.The antenna can work in 2.4ghz～2.54ghz(4G),5.27ghz～5.4ghz(5G)frequency band,and maintain good radiation characteristics in dual-band;At the same time,the out-of-band signal suppression also reaches-10dB,and the antenna gain generates rectangular coefficients similar to the filter parameters.2.Metasurface has a special electromagnetic radiation characteristic,USES the multipath to feed the antenna coupling way,without any increase in array under the condition of yuan design complexity,more resonant mode combined with the cross coupling filter topology to inspire antenna radiation characteristics,within the passband using super polarization reverse characteristic on the surface of the circular polarized radiation.The antenna has simple structure,low profile and small size,and is suitable for general communication systems.3.Aiming at the fusion design of planar broadband antenna and filtering characteristics,a transmission line with low pass characteristics is designed by using CSRR-DGS on the basis of studying the theory of defective ground structure,and the influence of defective ground structure parameters on band-pass characteristics and return loss is studied.On this basis,a filter monopole antenna loaded with defective ground structure is proposed.The antenna works in the range of 2.8GHz～4.95GHz and has a bandwidth of 2.15GHz.Without adding additional filter circuit,the out-band gain suppression of-13dB can be obtained by etching the pattern on the original metal ground plate of the antenna without changing the original in-band pattern and gain.