UPPER WLAN BAND NOTCHED UWB MONOPOLE ANTENNA USING COMPACT TWO VIA SLOT ELECTROMAGNETIC BAND GAP STRUCTURE

Electromagnetic Band Gap (EBG) structures can be employed near the feed line of a UWB monopole antenna, to reject the already existing narrowband radio signals operating within the spectrum of an Ultra Wide Band (UWB) antenna. Multiple EBG structures are required to reject multiple interfering bands. However, since the ground plane of a monopole antenna is limited, there is a need for compact EBG structures. This paper presents the application of a Two Via Slot (TVS) EBG to reject the interfering upper Wireless Local Area (WLAN) band (5.725 GHz–5.825 GHz) from the spectrum of a fork-shaped UWB monopole antenna. The simulated results demonstrate that the TVS EBG gives better performance in terms of higher and sharper Voltage Standing Wave Ratio (VSWR) value at the rejection band while occupying least ground plane area than Conventional Mushroom Type (CMT) EBG, Edge Located Via (ELV) EBG, slotted-patch ELV EBG, and semi-circular EBG. The proposed design is fabricated and measured. The measurement results prove that the antenna successfully achieves wide impedance bandwidth from 3 GHz to 12 GHz while rejecting the frequencies from 5.4 GHz to 5.9 GHz.