Research Article A Miniaturized Dual-Band Short-Ended ZOR Antenna with Backed Ground Plane for Improved Bandwidth and Radiation Efficiency Rajkishor Kumar , 1 Avinash Chandra , 1 Sreenath Reddy Thummaluru , 2 Mohammad Monirujjaman Khan , 3 and Raghvendra Kumar Chaudhary 4 1 School of Electronics Engineering, Vellore Institute of Technology, Vellore, Tamil Nadu 632014, India 2 Department of Electronics and Communication Engineering, Indian Institute of Information Technology Design and Manufacturing (IIITDM), Kancheepuram, Chennai 600127, India 3 Department of Electrical and Computer Engineering, North South University, Bashundhara, Dhaka-1229, Bangladesh 4 Department of Electrical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India Correspondence should be addressed to Mohammad Monirujjaman Khan; khandrmohammadmonirujjaman@gmail.com Received 10 August 2022; Revised 13 September 2022; Accepted 29 November 2022; Published 9 February 2023 Academic Editor: Herv´ e Aubert Copyright © 2023 Rajkishor Kumar et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Tis paper presents a miniaturized planar dual-band short-ended metamaterial antenna with the backed ground plane to improve antenna bandwidths and radiation characteristics. Te 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). Te proposed antenna ofers a short-ended MTM, and hence the ZOR frequency is controlled by a series of LC lumped parameters. Te proposed antenna ofers 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. Te overall electrical size of the designed antenna is 0.225λ 0 × 0.144λ 0 × 0.0144λ 0 atZOR(f 0 � 2.70 GHz), where λ 0 is the free space wavelength; therefore, it is applicable for diferent 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 efciency, and also ofers om- nidirectional radiation patterns in the E-plane and dipolar type radiation patterns in the H-plane, respectively. 1. Introduction In a metamaterial antenna, the zeroth-order resonance is a special property derived by plotting the dispersion char- acteristics of composite right- or left-handed transmission lines (CRLH-TL). In the zeroth-order resonant (ZOR) mode, the physical size of the antenna is independent of the resonant frequency [1–8]. Since metamaterial (MTM) is an artifcial structure, it has some unnatural properties, such as group and phase velocities being in opposite directions and a nonlinear progressive phase [9, 10]. Several works have been performed based on the ZOR property to miniaturize the size of the antenna, despite the fact that it has a narrow bandwidth, negative gain, and poor radiation efciency [11, 12]. In recent years, numerous methods have been introduced to improve the impedance bandwidth, gain, and radiation efciency of metamaterial antenna [13]. Short- ended MTM antenna ofers designed fexibility for the an- tenna community to control ZOR frequency by varying series parameters [14]. Due to the recent requirement of diferent wireless communication bands in one system, dual or multiband antennas are more demanding to fulfll these Hindawi International Journal of Antennas and Propagation Volume 2023, Article ID 2478853, 8 pages https://doi.org/10.1155/2023/2478853