An electrically small inverted L‐shaped asymmetric coplanar strip‐fed antenna with split‐ring resonator for multiband applications

Abstract

SummaryIn this paper, an electrically small inverted L‐shaped asymmetric coplanar strip‐fed antenna with a split‐ring resonator structure is proposed for multiband applications. It possesses an extended monopole antenna and a rectangular split‐ring resonator (RSRR) structure. A monopole is responsible for generating the first and last resonance frequencies. Similarly, the RSRR structure produces center frequency (5.5 GHz) among three resonance frequency bands and improves impedance matching at a higher frequency. The antenna has an electrical size of 0.176 λ0 × 0.096 λ0 × 0.012 λ0. The proposed antenna has a triband resonance response at 2.45, 5.5, and 7.5 GHz with a bandwidth of 560 MHz, 680 MHz, and 3 GHz, respectively, which covers WiBro (2.3 GHz), WLAN (2.4/5.2 GHz), WiMAX (2.5/5.5 GHz), X‐band downlink (7.4 GHz), and ITU band (8.5 GHz). The antenna design is simulated and validated with measured results and has better radiation characteristics in all the required frequency bands. The presence of metamaterial property in the proposed RSRR is analyzed. The design is an electrically small antenna, and it has a radian sphere (ka) = 0.64. Further, the proposed antenna performances are compared with the various existing literature.