Frequency- and time-domain analysis of a novel UWB reconfigurable microstrip slot antenna with switchable notched bands

A novel reconfigurable microstrip slot antenna with capability of switchable frequency notched bands for ultra-wide-band (UWB) applications is presented. The feed line is tapered to provide UWB matching condition. Two parasitic elements are attached to two sides of patch having a square slot for improvement of frequency band response. An inverted -shaped parasitic element is placed inside the slot in patch to produce a notch at wireless local area network (WLAN) frequency band (5.1-5.7GHz). A rectangular split ring resonator is placed on the back side of microstrip slot antenna to produce a notch at downlink X-band for satellite communication systems (7.2-7.8GHz). Reconfigurability of proposed antenna is obtained by placing PIN diodes at appropriate places to achieve four different operations, namely UWB coverage, UWB coverage with single band notch at WLAN, UWB coverage with single band notch at downlink X-band and UWB coverage with double band notch at WLAN and downlink X-band. The first case achieves fractional bandwidth of 123% (3.1-13GHz). Antenna performance is studied in frequency and time domains. The bias circuits of PIN diodes are placed on antenna structure and are considered in simulations. A prototype model of proposed antenna is fabricated and measured to demonstrate its desirable features.