Frequency reconfigurable Vivaldi antenna

A novel Vivaldi antenna with a capability to operate in wideband or narrowband operations is presented. Four pairs of switchable ring slots were introduced to change the wideband properties into narrower pass bands. A wideband of 1–3.2 GHz and three narrowband operative states were achieved. Experimental results on a prototype antenna with pin diodes switches fully demonstrate the performances of the proposed designs. The antenna could be a promising solution for application requiring frequency reconfigurable antennas such as a small base station or a portable equipment antenna in a cognitive radio application.