Research On Planar Antenna Based On SRR/CSRR Structure

Since SRR structure has been raised,it has become a research hot spot for researchers.It can be used not only as a component of artificial metamaterials,but also in the design of microwave devices such as filters and especially antenna applications,which are particularly common.Antenna is an essential component of modern communication systems,it plays a role in transmitting and receiving electromagnetic waves in the system,which implies that the performance of the antenna will directly determine the efficiency of the whole system.Therefore,how to apply the SRR structure into a commonly used microwave antenna is a very interesting and challenging topic.In this paper,various types of microwave antennas are designed by using SRR structure,the specific work includes the following two aspects:1.Design of UWB notch antenna1)Based on the theory of UWB planar antenna,an ultra wideband planar monopole antenna is designed,and then the miniaturization and impedance matching are obtained by improving the radiation patch and ground plane structure.The quadruple band-notched characteristics is realized by etching a codirectional CSRR on the radiating element and loading the symmetrical SRR on both sides of the feedline.The study shows that the codirectional CSRR structure is easy to design and adjust,and can be effectively applied to small-sized antenna elements.2)Then,a two-unit polarization diversity MIMO antenna and a four-unit MIMO antenna are obtained by using the orthogonal arrangement of the units.This reasonable layout enables the antenna to avoid the complex decoupling structure.3)In addition,a miniaturized UWB angular diversity MIMO antenna is proposed,it uses "symmetrical cut half method" to achieve miniaturization.The overall size of antenna is smaller than the most of ultra wideband angle diversity MIMO antenna that has been reported.At the same time,a compact notch structure is designed using the codirectional rectangular double-ring CSRR and a quarter-wavelength L-slot.The antenna uses T-shaped strip and CSRR slot to improve the isolation of the antenna,and achieved the desired results.2.Design of high isolation MIMO antenna1)An inverted F-type MIMO antenna is designed based on the inverted-F antenna theory and the miniaturization technology.Its parasitic branches in the ground plane is aiming to achieve dual-band work performance.Since the two-unit spacing is only 0.16g?,a compact LSRR structure is introduced in the ground plane to improve the isolation of the antenna.Then this paper analyzes the quantity,size,surface current and medium parameters of the LSRR structure.Simulation and measurement results show that the antenna can perform highly to achieve a high degree isolation goals.2)This paper further reduces the size of the dual-band IFA and loads the L-shaped parasitic branches to get a miniaturized tri-band inverted F-type MIMO antenna.The antenna uses a more compact,more simple LSRR structure,and the single negative magnetic permeability bandwidth of two kinds of LSRRs are analyzed and discussed by electromagnetic parameter extraction.Simulation and measurement results show that the antenna has high isolation,good impedance matching performance,and good application prospects.3)In addition,a dual-frequency monopole MIMO antenna is designed and the mutual interference between two antenna elements is suppressed by using the band-stop electromagnetic transmission characteristic of SRR.The research shows that this method has the advantages of simple design and easy integration.