A Miniaturized Printed Circuit CRLH Antenna-based Hilbert Metamaterial Array

With the development of communication systems and antennas, various challenges arise that require antennas of small size with enhanced performance. Metamaterials (MTM) defects introduced a considerable solution to such a challenge. Therefore, in this paper, a lightweight with low profile antenna is designed based on a novel design of a Composite Right/Left-Handed CRLH-MTM Hilbert array. The proposed CRLH-MTM unit cell consists of a T-symmetric CRLH unit cell conjugated to the 3rd-order Hilbert on the ground plane through a T-stub structure to enhance the gain-bandwidth product. CST-MWS is used to stimulate and design the proposed antenna structure. The antenna parameters are optimized to evaluate the antenna performance in gain and S11. As a result, the antenna can operate forward and backwards with a large scanning angle ranging from +34o to -134o with changing frequency, and dual-band extended from 3.3GHz to 4.2GHz 4.86GHz 5.98GHz with a maximum gain of 7.24dBi and 3.74dBi, respectively. The beam steering is achieved by trough controlling the switching operation of PIN diodes. As a result, the antenna can scan up to 8° from 34° to 42° at 3.5GHz with constant gain along with the operating range

Performance Evaluation of Triple band Microstrip Antenna using Hybrid SRRs on Fractal Ground Plane

A single-band monopole antenna, transformed into a triple-band antenna for S-band and C-band applications is reported in this paper. This transformation is done with the help of two different hybrid SRR unit cells, which are embedded on the truncated ground plane of the antenna. These hybrid SRR unit cells are created by combining square split ring and circular split ring into two different configurations. Simulated results are in coherence with the measured results and analysis is provided to evaluate the efficacy of the design. This analysis can be used to estimate the usefulness of metamaterial unit cells in generating multiple frequency bands. The operating frequency bands measured are 2.72-2.83GHz, 3.54-4.35 GHz, and 4.72-5 GHz respectively. These bands are being used in the mid-band frequency range of 5G communication in many countries. The developed antenna is miniaturized to the size of 0.19λ0 ×0.25λ0 (λ0 is the free space wavelength at 2.72 GHz). Two objectives i.e., miniaturization and multi-banding are fulfilled in a single design. The introduction of different hybrid SRR unit cells at defective ground plane causes multi-banding and resonance of a unit cell at a lower frequency leads to an increase in the effective electrical length of the antenna without increasing its physical size. The metamaterial characteristic of the unit cells is also verified in the article

Printed closely spaced antennas loaded by linear stubs in a MIMO style for portable wireless electronic devices

This article belongs to the Special Issue Transmit and Receive Techniques for Next Generation Massive MIMO Systems.An easy-to-manufacture and efficient four-port-printed Multiple Input Multiple Output (MIMO) antenna operating across an ultra-wideband (UWB) region (2.9–13.6 GHz) is proposed and investigated here. The phenomenon of the polarization diversity is used to improve the isolation between MIMO antenna elements by deploying four orthogonal antenna elements. The proposed printed antenna (40 × 40 × 1.524 mm3) is made compact by optimizing the circular-shaped radiating components via vertical stubs on top of the initial design to maximally reduce unwanted interaction while placing them together in proximity. The measurements of the prototype MIMO antennas corroborate the simulation performance. The findings are compared to the recent relevant works presented in the literature to show that the proposed antenna is suitable for UWB MIMO applications. The proposed printed UWB MIMO antenna could be a good fit for compact portable wireless electronic devices.This project received funding from Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant 801538. Furthermore, this work was partially supported by the Researchers Supporting Project number (RSP-2021/58), King Saud University, Riyadh, Saudi Arabia