Design of absorber based on metamaterial structure to improve the isolation of WCDMA indoor repeater

In this paper, WCDMA indoor repeater antenna for high isolation using the absorber based on Metamaterial structure is proposed. The proposed antenna is composed of main patch, parasitic patch and proposed absorber. The required WCDMA bandwidth is obtained by utilizing the coupling between the main and parasitic patches. The absorber consists of split ring resonators (SRRs) and complementary spiral (CS) structure. The size of the absorber based on metamaterial structure is 14 mm × 14 mm, the absorption is about 93 % at 2.18 GHz. The isolation characteristic of proposed WCDMA indoor repeater antenna is improved by using the proposed absorber. The proposed WCDMA indoor repeater antenna has a gain higher than 6 dBi with a VSWR less than 2, and isolation between the service and donor antenna greater than 80 dB over the WCDMA band from 1.92 GHz to 2.17 GHz, respectively. The volume of the proposed repeater antenna is 90 mm × 90 mm × 44.8 mm.