Research Of Microstrip Antennas And Filters Based On SRR

Left-handed material (LHM) is a newly discovered artificial metamaterial with negative permittivity and negative permeability simultaneously. From the first realization of LHM at 2000, it has been the front and focus. In the past few years, split ring resonators (SRRs) and complementary split-ring resonators (CSRRs) have attracted considerable attention because of their unusual electromagnetic properties, small unit electric size and can be applied to antennas, reflectors, filters, perfect lens and so on. With the rapid increase in communication capacity and new functions such as GPS, Bluetooth and wireless communication, it is fair to expect antennas and components with small size, wide band and multiband. In this paper the characteristics of SRR and CSRR are mainly analyzed. Then SRR and CSRR are applied in microstrip antenna and microwave components. The original works and valuable results of this dissertation are as follows:First, A novel planar ultra-wideband (UWB) antenna, application of split ring resonators, fed by planar coplanar waveguide (CPW) is proposed in this paper. Three SRRs with varying proportionally dimension is designed as the radiation surface. A tapered feed line is adopted to improve the return loss performance in the required band. The proposed UWB antenna has a wide bandwidth from 1.1 GHz to 22 GHz , and all the return losses are less than - 10 dB in the whole band. The antenna radiates quasi-omnibearingly and quasi-symmetrically in the very wide frequency band.Second, the experimental verification of a novel approach to obtain multi-frequency performance based on a dipole loaded with SRRs is presented. These SRRs are electromagnetically coupled to the dipole. Thus, they can be printed next to the dipole or in the other side of the substrate and the dipole remains unchanged. For these reasons, arbitrary frequency can be achieved.At last, we present a miniaturized dual-passband filter module designed using double-split complementary split ring resonator (DS-CSRR) and split ring resonator (SRR). The use of SRR results is a significant size reduction of the filter comparing with edge-coupled-line filters. Two passbands are individually printed on two sides of the substrate, consequently providing a novel and compact integration. Coupling between two bands is weak, so they can be independently designed and tuned.