Planar UWB Antenna with 5 GHz Band Rejection Switching Function at Ground Plane

The design of an octagonal-shaped microstrip-fed planar monopole antenna for ultrawideband (UWB) operation is studied. Two inverted T-shaped slits are embedded on the ground plane to allow band rejection characteristic from 5 to 6 GHz (for VSWR < 2). To enable switching capability for this band rejection function, a PIN diode is connected to each slit via a specified chip inductor that will be further investigated. Several prototypes were constructed and the measured results show that the proposed antenna can provide an operating bandwidth from 3.07 to 10.7 GHz, except for the rejected band. Simulation analyses are also carried out to validate the experimental results.