Design of Compact Monopole Ultrawideband Frequency Reconfigurable Antenna

The wideband frequency spectrum, such as UWB, also consists some narrowband services like WiMAX and WLAN. Therefore, the possibility of interference between wideband and the narrowband services increases. Generally, an additional filter is used to overcome the interference issues, but, the use of additional filter increases the cost and complexity of the system. Earlier, a truncated patch antenna with C-shaped slot has been proposed to optimize the cost and complexity, but, it fulfils the band rejection requirement for WLAN (5-6 GHz), while, it does not support the reconfigurability. An optimized planar ultra-wideband (UWB) antenna with WLAN band-reconfiguration characteristic fed by a 50 Omega coplanar waveguide (CPW) has been proposed in this paper. In this proposed structure, the truncated metal patch consists two additional symmetrical open stubs and the patch and the stubs are connected through MEMS switches to achieve the reconfigurable property. The overall dimension of the antenna is 19x18x1.6 mm(3) and integrated on FR4 substrate. The proposed design has shown wideband impedance matching in terms of radiation pattern and gain along with reconfigurability.