Compact ultra-wideband antenna: improvement of gain and FBR across the entire bandwidth using FSS

In this paper, a highly compact ultra-wideband (UWB) monopole antenna with high gain is proposed. The UWB monopole antenna consists of U-shaped radiating patch. The ground plane comprises of edge-truncated partial rectangular metallic plane with a rectangular slot at the centre of the top edge. The proposed antenna having a very compact dimension of 16 mm × 22 mm × 1.6 mm is compatible and highly suitable for compact wireless systems. Further for enhancement of directivity of the UWB antenna, a patch type frequency selective surface (FSS) is placed below the antenna. The combined FSS-antenna structure operates with high gain (peak gain of 9.4 dBi) across the entire UWB range (3.1–18.6 GHz). The proposed design also offers an appreciably high front-to-back lobe ratio of ∼10 dB across the entire UWB range. The simulated results are verified experimentally and the results are discussed in detail. The overall dimension of the proposed FSS integrated composite antenna is 52 mm × 62.5 mm × 23.2 mm, which is highly relevant for high-gain applications.