Research And Design Of Antenna Based On Suspended Coplanar Waveguide (SCPW) Structure

With the continuous development of wireless communication technology,requirements for antenna bandwidth,gain,volume and other related indicators have become more and more stringent in recent years.In order to improve the performance of the antenna,more and more new antenna design techniques are proposed.The proposal of the suspended coplanar waveguide transmission line(SCPW)can provide a new idea for new antenna design.The use of SCPW transmission lines to design antenna has high design flexibility,low feeder loss,large available circuit design area,easy to achieve miniaturized antenna design,and the structure of antenna can be self-packaged.In this paper,the design and research of broadband filtenna,MIMO filtenna and low-profile high-gain antenna are carried out on the basis of SCPW transmission lines.First of all,this paper designed a broadband filtenna with self-packaged advantage based on the suspended coplanar waveguide structure using independent cavity technology.The integrated design of the filter and antenna made the leaf-shaped wide slot antenna has the characteristics of high-efficiency radiation within the working frequency band and effective energy radiation suppression outside the working frequency band,avoiding the direct connection between the antenna and the filter in the RF front-end circuit impedance mismatch,excessive volume and other problems.The working bandwidth of the broadband filtenna covered 2400MHz-4100MHz,the relative bandwidth is 52.3%.In the passband the maximum gain of filtenna is 3.87dBi,and the overall efficiency is above 75%,two gain zeros are generated at 1528MHz and 5432MHz outside the passband.The filtenna has good gain flatness,stable pattern and high polarization purity,can be well applied to mobile communication equipment in WiMAX frequency band and Sub-6G frequency band.Secondly,combining the advantages of the filtenna and the MIMO antenna,this paper proposed a four-port MIMO filtenna with adjustable gain zeros based on a suspended coplanar waveguide transmission line.By using the separated electric/magnetic coupling path and the coupling path between the feed and the antenna,two adjustable gain zeros are generated on both sides of the passband of the MIMO filtenna unit.The position of the gain zeros can be independently controlled by adjusting the strength of electric and magnetic coupling.Then,placing the MIMO filtenna units in four cavities using independent cavity technology.Utilize the natural structural advantages of the suspended coplanar waveguide to suppress the coupling of the surface wave of the MIMO filtenna,and use the filtering radiation effect to further reduce the coupling between the MIMO filtenna.The MIMO filtenna bandwidth covered 5120MHz-5312MHz and the isolation between antenna elements is 25.3dB,the gain is 2.8dBi.Finally,the design of high gain antenna with low profile and its array is carried out.The design method of high-gain antenna with low profile condition is mainly studied,the lower cavity of the suspended coplanar waveguide structure is used as the reflecting cavity to enhance the directivity of the antenna unit;The antenna bandwidth is expanded by increasing the parasitic element to introduce the resonance point.The outer side wall of the five-layer dielectric board is coated with copper to expand the reflector structure,keeping the antenna pattern stable.The profile height of the antenna reached 1/10?,the 3×2 array arrangement method is used to group the antenna elements for further improving the gain of the antenna.The working bandwidth of the array antenna covered 5030MHz-5960MHz,and the maximum gain achieved 16.3dBi.The technical methods in this paper lay the foundation for the subsequent design and the practical engineering application of the suspended coplanar waveguide antenna.