This review paper combs through reports that have enhanced antenna gain for ultra-wideband (UWB) frequencies using frequency-selective surface (FSS) techniques. The FSS techniques found across the research landscape were mapped onto a taxonomy in order to determine the most effective method for improving antenna gain. Additionally, this study looked into the motivation behind using FSS as a reflector in UWB frequencies to obtain directional radiation. The FSS suits multiple applications due to its exceptional ability to minimize power loss in undesired transmission areas in the antenna, as well as to hinder the interference that may occur from undesirable and wasted radiation. An efficient way to obtain constant gain over a wide range of frequencies is also elaborated in this paper. Essentially, this paper offers viable prescription to enhance antenna gain for UWB applications. Methods: A comprehensive study was performed using several imminent keywords, such as “high gain using FSS”, “gain enhancement using FSS”, “high gain UWB antennas”, and “gain enhancement of UWB antennas”, in different modifications to retrieve all related articles from three primary engines: Web of Science (WoS), IEEE Xplore, and Science Direct. Results: The 41 papers identified after a comprehensive literature review were classified into two categories. The FSS single- and multi-layer reflectors were reported in 25 and 16 papers, respectively. New direction: An effective method is proposed for FSS miniaturization and for obtaining constant gain over UWB frequencies while maintaining the return loss at −10 dB. Conclusion: The use of FSS is indeed effective and viable for gain enhancement in UWB antennas. This systematic review unravels a vast range of opportunities for researchers to bridge the identified gaps.

This paper aims to present a miniaturised and new design of ultra-wideband (UWB) frequency selective surface (FSS) with stopband characteristics for electromagnetic (EM) shielding applications. The modelled FSS used the integration of a two parallel conductive metallic patch with a circular loop structure. The FSS provided a UWB stopband filter response covering a bandwidth of 10.5 GHz, for frequencies from 2.2 GHz to 12.7 GHz. The proposed FSS had a compact physical dimension of 5 mm × 5 mm × 1.6 mm, with a printed array of 19 × 19 FSS unit cells. An equivalent circuit configuration (ECC) was used to verify the FSS unit cell structure’s performance. The proposed FSS was identified to contribute towards independent polarisation for obliques incidences transverse electric (TE) and transverse magnetic (TM) polarisations from 0° to 20°. Besides, the performance of the proposed FSS is stable over a wide range of incident angles for TE and TM polarisations.

A new design for array leaky-wave antenna to achieve high elevation angle and obtain high radiation pattern on boresight is proposed in this study. Two half-width microstrip leaky-wave antennas are placed horizontally and used one fed probe between them. The other side of the halfwidth used lumped element (matching load 50 ohm). An array of vias was used to connect the radiation element with the ground plane to make the microstrip line work in the first high order mode. The main beam direction can be changed by control the reactance of the microstrip line with the free edges of radiation elements and the ground. This controlling led to the use of two vertical vias array alone the radiation element of each antenna. The simulated result produced a high matched bandwidth of the array of 800 MHZ (4.2- 5) GHz. The direction of the main beam scanning towards in boresight with maximum gain 12.9 dBi. The elevation angle can be scanning between 22o to 65o. The proposed antenna is promising to the C-band applications.