Ultra-wideband coplanar waveguide-fed hexagonal slot antennas with WLAN band rejection

In this paper, printed regular hexagonal slot antenna fed by a coplanar wave guide line has been presented for ultra wide bandwidth. The hexagonal shape stub is used. The antenna is then modified to possess band rejection at the wireless local area network (WLAN) (5.1-5.8 GHz) by a C-shape slot within the exciting stub. The length and width of the C-shape slot offer sufficient freedom for selecting and shifting the notched band. VSWR, impedance, gain and radiation characteristics are presented and discussed. From the results, it has been observed that, the impedance bandwidth, defined by 2≤VSWR, can reach a value of 6.5 GHz (3.1~9.6 GHz), while stop bands of 5.15 to 5.8 GHz. The proposed antenna gain varies 4 dB to 5.3 dB over the whole operating band excluding the notch band. Surface current distributions and transmission line model are used to analyze the effect of the slot.