Open-Slot Loaded Monopole Antennas for WLAN and UWB Applications

This paper focuses on planar CPW-fed dual-band rectangular monopole antennas with variation of slot-loaded and taper-fed designs. Monopole antennas of shapes utilizing beveling or tapering technique such as triangle and rectangle could easily broaden the impedance bandwidth to satisfy UWB band requirements. Furthermore, the dual-band operation of both UWB (3.1-10.6 GHz) and existing WLAN 802.11b/g (2.4-2.5 GHz) has gain increasing interests in the backward compatible design if the multi-band OFDM technology is adopted as UWB standard. In this case, the antenna should be designed as dual-band with a notch in the 2.5-3.1 GHz band to match the FCC spectrum mask. Using a slot-loaded band rejection technique, we propose a open-slot loaded antenna to achieve the band notch function. This paper also investigates the effect of the tapered feed on the performance of phase linearity. It concludes that the antenna of a circular tapered feed has a better phase linearity