A Reconfigurable Dual Sharp Notch-band UWB Antenna

This article presents a dual notch band Ultra-wideband (UWB) reconfigurable antenna. The antenna consists of a radiation patch, coplanar ground, electromagnetic bandgap (EBG) structures, and switches. The lower edges of the radiating patch are truncated to enhance the antenna's UWB spectral bandwidth, and pairs of EBG structures are utilized to form sharp-notch characteristics. The antenna is made reconfigurable by using RF switches (diodes) and has four modes of operations. Based on the simulation results, the presented antenna operates at a bandwidth of 3.1–11.8 GHz for |S11|<-10. The antenna is small in size having dimensions of 20 × 27 × 1.52 mm³, and also offers a good radiation pattern and stable gain.

I. Introduction

The Ultra-wideband (UWB) is a radio technology that can share information over a large portion of the wireless spectrum using very low energy levels. UWB has been used in non-cooperative radar image analysis. The majority of recent applications are focused on sensor systems, accurate location finding, and tracking. High-end smartphones began to include UWB support [1]-[3]. The frequency range designated for UWB systems is from 3.1 GHz to 10.6 GHz. The sub-narrow bands coexist within the UWB spectrum such as Mid-band (3.4-3.8 GHz), Wireless LAN (5.15-5.85 GHz), and Satellite downlink band communication systems are creating interference. Therefore, there is a huge demand for UWB antennas with stop-band features. The addition of filters to the antenna causes an increase in volume. Therefore, notch antennas with modifications in basic design can avoid this issue.