A Miniaturized Dual-Band Short-Ended ZOR Antenna with Backed Ground Plane for Improved Bandwidth and Radiation Efficiency

This paper presents a miniaturized planar dual-band short-ended metamaterial antenna with the backed ground plane to improve antenna bandwidths and radiation characteristics. The proposed dual-band metamaterial (MTM) antenna has been made up of the composite right- or left-handed transmission line (CRLH-TL) concept. Here, the backed ground plane has been employed to generate an extra coupling capacitance (C-C), which shifts the ZOR frequency in the lower band while also improving ZOR matching and increasing the impedance bandwidth of the higher-order mode. In this proposed MTM antenna, interdigital capacitance (IDC) has been used in place of a simple series gap, which shifts the higher-order impedance bandwidth into a lower frequency band for second-band Wi-MAX applications (3.3-3.7 GHz). The proposed antenna offers a short-ended MTM, and hence the ZOR frequency is controlled by a series of LC lumped parameters. The proposed antenna offers dual-band behavior with measured -10 dB impedance bandwidths of 5.55% and 41.57% at centered frequencies of 2.70 GHz and 4.33 GHz, respectively. The overall electrical size of the designed antenna is 0.225 lambda(0) x 0.144 lambda(0) x 0.0144 lambda(0) at ZOR (f(0) = 2.70 GHz), where lambda(0) is the free space wavelength; therefore, it is applicable for different Wi-MAX application bands (2.5-2.7 GHz/3.3-3.8 GHz). Furthermore, the proposed dual-band MTM antenna provides compactness, low loss, stable gain, and radiation efficiency, and also offers omnidirectional radiation patterns in the E-plane and dipolar type radiation patterns in the H-plane, respectively.

Automated summary

This paper presents a miniaturized planar dual-band short-ended metamaterial antenna with a backed ground plane to improve antenna bandwidths and radiation characteristics. The proposed antenna utilizes a composite right- or left-handed transmission line (CRLH-TL) concept and interdigital capacitance (IDC) to achieve dual-band behavior. The antenna offers compactness, low loss, stable gain, and radiation efficiency, making it suitable for different Wi-MAX applications.