Photonic crystal-based ultra-wideband bow-tie antenna for high-gain and THz frequency-dependent beam scanning

Gherbi, Aicha, Messaoudene, Idris, Khodja, Khalida, Hedir, Abdallah, Belazzoug, Massinissa, Chennouf, Choumeyssa and Atia, Salim 2026. Photonic crystal-based ultra-wideband bow-tie antenna for high-gain and THz frequency-dependent beam scanning. Photonics 13 (4) , 312. 10.3390/photonics13040312

PDF - Published Version Available under License Creative Commons Attribution. Download (4MB)

Abstract

One of the strongest electromagnetic engineering approaches for enhancing antenna performance is the use of photonic crystal (PhC) substrates. This technique can be efficiently applied to antenna design and offers notable advantages, such as gain improvement, increased bandwidth, and frequency-dependent beam scanning. In this paper, a bow-tie dipole antenna has been developed for terahertz operation over the 0.39–1.3 THz band, presenting a novel structure capable of producing strong ultra-wideband (UWB) field enhancement within its feed gap. The feed gap between the two metallic arms has a slot width of 1.24 λ0 (λ0 is the wavelength in free space at a center range of 0.8 THz), which facilitates the generation of an enhanced electric field. The PhC substrate enables surface-wave control through dispersion engineering, thereby enhancing the radiation efficiency of the antenna. The proposed antenna exhibits a radiation efficiency of approximately 73–93% over the entire UWB frequency band. Furthermore, the PhC substrate antenna achieves a maximum gain of 21 dB, exceeding that of a homogeneous-substrate THz bow-tie antenna by at least 3.3 dB. The results indicate that the antenna achieves |S11| < −10 dB impedance matching over the bandwidth of 105.9%, ranging from 0.4 to 1.3 THz. The proposed bow-tie dipole antenna integrated with a PhC substrate demonstrates a wide beam-scanning capability from −54° to +74° across the 0.39–1.16 THz band, while maintaining a compact footprint of 14.9 λ0 × 22.4 λ0. This combination of wide scanning, broad bandwidth, and ultra-low profile represents a notable advancement in the development of compact THz radiating structures.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Schools > Engineering
Additional Information:	License information from Publisher: LICENSE 1: URL: https://creativecommons.org/licenses/by/4.0/, Start Date: 2026-03-24
Publisher:	MDPI
Date of First Compliant Deposit:	9 April 2026
Date of Acceptance:	18 March 2026
Last Modified:	09 Apr 2026 09:45
URI:	https://orca.cardiff.ac.uk/id/eprint/186287

Actions (repository staff only)

Edit Item