Wideband dual-frequency CPW-fed triangular monopole antenna for DCS/WLAN application

A novel and simple wideband dual-frequency design of a coplanar waveguide (CPW)-fed triangular planar monopole antenna is proposed. By the proper choice of the flare angle for the triangular patch and the gap distance for the CPW feeding structure, an additional resonant mode and wide impedance matching can be realized. Both theoretical and experimental results of bandwidths and radiation characteristics for prototypes of the proposed antenna have been presented and discussed. The measured -10dB impedance bandwidth at the lower band (1.71 GHz) is about 240 MHz and that at the upper band (5.62 GHz) reaches about 2 GHz, which cover the DCS1800 and the IEEE 802.11a 5.2/5.8 GHz WLAN standards, respectively. Good monopole-like radiation patterns with antenna gains of 2.3–3.6 dBi and 3.9–5.6 dBi over the lower and upper bands, respectively, have also been obtained.