Study of Dual Stopbands UWB Antenna with U-slot and V-slot DGS

A peach-like ultra-wideband (UWB) planar monopole antenna (PMA) with dual stopband characteristic is presented in this paper. It is designed to work on a substrate Rogers RT5880 that has a thickness of 1 mm and relative permittivity of 2.65. The proposed antenna is fed by microstrip line; the U-slot is used to reject the frequency band (3.3–4.2 GHz) limited by IEEE 802.11a or HIPERLAN/2. Another rejection band (5.15–5.825 GHz) limited by IEEE 802.11b and C-band satellite communication systems is obtained by using the V-slot defected ground structure (DGS). The size of the antenna is 33 mm × 35 mm. Effects of varying the interior degree of the V-slot DGS and the length of the U-slot on antenna performance have also been studied. Measured result shows the designed antenna with an impedance bandwidth covering at least 3.11 to 15 GHz assuming a 10 dB return loss, except 5.04–6.42 GHz and 3.35–4.24 GHz band. Also the simulated results show that the antenna has omnidirectional radiation patterns in the x-z plane and good gain flatness.