Enhanced gain and broadband of endfire antenna by using I-shaped resonator structures

Abstract

A broadband high‐gain periodic endfire antenna is presented in this article. The broadband is achieved by using a planar out‐of‐phase power divider with ultra‐wideband performance and periodic dipole elements. The device uses two substrates with a common ground plane. A coupling between two microstrip lines on the top and bottom substrate layers through a slot in the common ground plane, and a transition from two microstrip lines to a parallel stripline are used to achieve an ultra‐wideband operation. The gain enhancement is achieved by loading with an I‐shape resonator (ISR) structure in the endfire direction. The effect of the I‐shape unit cell structure on the gain enhancement is investigated. Both the ISR‐loaded antenna and unloaded one are fabricated to verify the predictions. The measurements show that ISR‐loaded antenna presents gain of about 7 dB‐10 dB in the whole working band (3 GHz‐11 GHz), which is about 2 dB‐3.5 dB more than the unloaded one. The proposed antenna can be using in wireless communication systems for its advantages of broad bandwidth and high‐gain.

Overview of Planar Antenna Loading Metamaterials for Gain Performance Enhancement: The Two Decades of Progress

“…The gain of bow-tie end-fire antenna is promoted by 1.5-3.5 dB over 5.1-8.3 GHz with a reduction in the side lob level [117]. In parallel, gain enhancements of 2-3.5 dB over 3-11 GHz and 2 dB over 4.5-9.5 GHz were achieved for periodic end-fire antenna and quasi-Yagi antenna in [118] and [119], respectively. Wang et al [120] presented 2 × 5 H-shaped resonator (HSR) unit cells to boost bow-tie gain.…”