Dual-Band Circularly-Polarized EBG-Based Antenna for Wi-MAX/WLAN/ISM Band Applications

A co-planar waveguide (CPW)-fed dual-band circularly-polarized (CP) disc-shaped monopole antenna with an electromagnetic band gap (EBG) array is presented for Wi-MAX, WLAN, and ISM band applications. The proposed monopole antenna is comprised of an arc-shaped stub (in the middle), a C-shaped strip (on the left), and an inverted L-shaped strip (in the right). The circular polarization is produced by truncating an arc in the T-shaped radiator, and the antenna is placed over an EBG array to achieve broader impedance and axial ratio bandwidths. The impedance bandwidth and axial ratio bandwidth (ARBW) in the first resonating band are 36.73% (2–2.9 GHz) and 21.16% (2.24–2.77 GHz), respectively. The antenna covers (2.4–2.48 GHz) WLAN/ISM band, (2.5–2.69 GHz) Wi-MAX band, and (2.38–2.49 GHz) Bluetooth application. The impedance bandwidth in the second resonating band is 6% (5.65–6 GHz), which covers (5.72–5.87 GHz) ISM band and (5.72–5.85 GHz) WLAN band. The CPW-fed disc-shaped antenna with an EBG array has dual band radiation characteristics, improved gain and radiation efficiency, compact size, and simple, light weight, and easy design with no vias required. The radiation characteristics of the proposed antenna are measured, and they agree well with the simulated results.