Dual-band slim inverted-F antenna with enhanced operational bandwidth

In this article, the design of a dual-band slim inverted-F antenna with an enhanced operational bandwidth is presented. Initially, a slim inverted-F antenna for operation in 850 and 1900 MHz bands supported by a large ground plane of 120 x 40 mm is introduced. This antenna offers dual band operation but with narrow bandwidth around each desired frequency. To reduce its ground plane length to 90 mm as well as to improve its operational bandwidth, a ground slot and a strip are introduced. By the proper placing of the slot and the strip, the lower frequency bandwidth is improved, while the good performance at the upper band is maintained. The designed antenna is fabricated and experimentally tested showing operational bandwidths covering GSM850 and PCS1900, with reference to the 6 dB return loss (VSWR 3:1). Its radiation patterns are omnidirectional at the lower band and become directional at higher frequencies, with the gain varying between -1 and 3 dBi. (C) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:684-689, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26643