Application Of Metasurface On Reconfigurable Microstrip Antenna

Microstrip antenna is a mature,enduring and developing research field.Microstrip antenna has obvious advantages such as small size,low profile and so on,but there are also disadvantages such as low gain and narrow bandwidth.Metasurface is a rising and popular research area which can improve the performance when applied in microstrip antenna.For example,frequency reconfigurable metasurface can continuously adjust the operating frequency of mircostrip antenna,thus reducing the number of antennas processed.In addition,antennas which only work in single polarization mode can be reconstructed to achieve a variety of polarization modes by using polarization reconfigurable metasurface.Generally,if the metasurface is designed properly,the gain and radiation pattern of microstrip antenna can also be improved.Firstly,we discuss the design process of frequency reconfigurable metasurface,polarization reconfigurable metasurface and related microstrip antennas.Also,we adopt the scattering parameter retrieval method to illustrate how the frequency reconfigurable metasurface composed of elliptic elements can realize frequency-reconfiguration.Moreover,resonant frequency of the microstrip patch antenna can be continuously changed from 5.0GHz to 5.6GHz by mechanically ratate the upper metasurface composed of square ring structure metal elements.In this paper,another polarization reconfigurable metasurface are proposed which can switch the polarization mode of mocristrip antenna at 5GHz between linear polarization(LP),left-hand circular polarization(LHCP)and righ-hand circular polarization(RHCP).On the basis of the previous design,two different types of metasurface are applied to the same microstrip antenna,the whole metasurface antenna operates at 4GHz and 5GHz which could be reconfigured in frequency and polarization respectively and mutually unaffected.Futhermore,the preceding polarization reconfigurable metasurface is improved,and a method to improve the polarization conversion bandwidth by changing the distance between metasurface,microstrip slot antenna and metal reflector is proposed which doubles the axial bandwidth(4GHz-5GHz)of whole metasurface antenna.