Abstract
In this paper, a planar monopole antenna with a tunable notch band for ultra wideband (UWB) applications is proposed. The antenna consists of an elliptical radiator, a microstrip-feed line and a ground plane. A meander-defected-ground structure (meander-DGS) etched on the ground plane is used to create a notch. A variable capacitor placed on the meander-DGS structure is used to tune the frequency of the notch band. The antenna is designed on a 30 mm (W) x 39.1 mm (L) x 0.762 mm (h) substrate with a relative permittivity of 3.48 and a loss tangent of 0.004. The antenna is studied by using computer simulation. The results show that the notch band can be tuned from 5.5 to 9.6 GHz by varying the capacitance from 1.7 to 0.07 pF, respectively.