A Simple and Compact CPW-Fed UWB Antenna with WLAN Band Rejection

Abstract

A new and simple ultra wide band (UWB) antenna fed by a coplanar waveguide (CPW) with notched bands at 5.8 GHz is presented in this paper. The physical dimension of this antenna is 17.5 ⨯ 17.5 mm2 which is considered as one of the smallest UWB antennas with band notched characteristics in the literature. The notched frequency band is created by cutting an elliptical slot of radii $a$ and $b$ and inserting a resonator stub in the radiating patch. The lengths of these radii and stub are used to adjust the centre notched frequency and the rejection band. The fabricated antenna has a broad bandwidth ranging from 3 to 15.2 GHz (based on return loss < −10 dB) with controllable notched band for WLAN applications. The experimental radiation patters are nearly omnidirectional and stable over the entire operating bandwidth in the H-plane and nearly bidirectional with two nulls in the E-plane. The very compact size and the good electromagnetic property of this proposed antenna makes it a good candidate to be integrated into portable devices for UWB systems.