Compact Triband ACS-Fed Monopole Antenna Employing Open-Ended Slots for Wireless Communication

A compact triband asymmetric coplanar strip (ACS)-fed printed monopole antenna employing open-ended slots for wireless communication is presented. The proposed antenna is composed of an ACS-fed monopole and two special open-ended slots, which occupies a very compact size of 27.5 $,\times,$ 13 mm $^2$ . By carefully selecting the lengths and positions of these slots, good dual stopband rejection characteristic can be achieved. The three obtained bands of 2.35–2.53, 3.34–3.85, and 5.05–6.28 GHz can successfully cover the WLAN and WiMAX operation bands. The principle and key parameters of the slot in producing notched band are analyzed in detail. The measured results demonstrate that the proposed antenna has good omnidirectional radiation patterns with reasonable gains across the operating bands, which is suitable to be integrated within the portable device for wireless communication.