A compact E-shaped antenna with C-shaped slots and a back-patch for multiband applications

We present the design of a tri-band E-shaped printed antenna with C-shaped slots. A Rectangular patch etched with an n-shaped slot is added at the back of the substrate to enhance the bandwidth and the return losses of the resonant bands - particularly, that of the second band. Our antenna is designed to operate at 1.51/2. 46/6.11 GHz. As can be observed from the experimental results, it has 10 dB bandwidths of 157 MHz (1.416 to 1.573 GHz) 358 MHz (2.221 to 2.579 GHz) and 367 MHz (5. 918 - 6. 285 GHz) The first two bands cover the LTE, Bluetooth, IEEE 802.15.4 ZigBee and IEEE 802.11 WLAN applications. The third resonant band covers the unlicensed 6 GHz band which is widely implemented in wireless power transmission, as well as, RFID and satellite communications. In order to ease wireless congestion, the 6 GHz band is also currently being considered by the FCC to be opened up for the use of WiFi applications. Our antenna is fabricated on a single-sided FR4-epoxy, and it constitutes a compact size of 34 mm x 36 mm x 1.6mm or 0.17 lambda x 0.18 lambda times0.0081 lambda, (based on the 1.51 GHz lowest resonant frequency) The antenna exhibits omnidirectional radiation patterns at the three resonant bands.