A Planar UWB Antenna with Switchable Single/Double Band-Rejection Characteristics

In this Paper, a reconfigurable antenna with capability to operate in the ultrawideband (UWB) mode from 2.85 to 14.4 GHz with switchable notch bands of 3.25–4.26 GHz, 5.1–5.9 GHz or 7.1-7.8 GHz, is presented. The proposed antenna has a simple configuration and compact size of 17 × 14 mm2. To make the band-notches, three methods (methods of slot antenna, parasitic patches and backplane structure) are used. To achieve the reconfigurability, three PIN diode are placed on the proposed antenna. A PIN diode is inserted over the L-shaped parasitic element and the rectangular patch, another one is placed between the two parasitic elements on the ground plane, and other across the square ring-shaped slot, respectively. Antenna performance can be changed by adjusting the status of the PIN diodes that make the band-notches in applications bands (WLAN, WiMAX/C-band and X-band). Good group delay and monopole-like radiation pattern characteristics are achieved in the frequency band of interest. The antenna performance both by simulation and by experiment indicates that it is suitable and a good candidate for UWB applications