Broadband antenna with asymmetrical radiating elements for cognitive radio system

Abstract

In recent years, cognitive radio system has been receiving particular attention as a promising technology in order to materialize efficient network access. In this paper, heightening upper limit frequency of the wideband antenna for cognitive radio system was investigated by employing three types of the antenna element variations. As a result, the antenna with the VSWR less than 2.0, employing asymmetrical elements, was obtained in the frequency range of 3.1 GHz to 18 GHz. Although the radiation patterns were slightly distorted, it was acceptable in practical use.