Slim wrapped inverted‐F antenna for GSM/DCS/PCS operation

In this letter, the design of a super slim multiband wrapped inverted‐F antenna that covers the frequency bands allocated for GSM, DCS, and PCS wireless services is described. In the first step, the quarter‐wavelength (at 850 MHz) open‐end arm of an inverted‐F radiator is folded and meandered. Then, the antenna is wrapped using a fourth‐order folding technique to reduce its projection area to only 40 mm × 10 mm × 3 mm. Full wave electromagnetic (EM) simulations show that the antenna excites a lower mode resonance at ∼850 MHz and a higher one at about 1900 MHz. Its radiation pattern is nearly omni‐directional with a gain of about 2.5 dBi at the lower band and 4.6 dBi at the upper band. A prototype of the proposed antenna is fabricated and tested. A close agreement between the simulated and measured results is achieved. The measured 6‐dB return loss or voltage standing wave ratio (VSWR) 3:1 bandwidths for the lower and upper resonances is 200 MHz (770–970 MHz) and 280 MHz (1710–1990 MHz), respectively. These bandwidths are sufficient to cover GSM 850/900/1800/1900 MHz, DCS 1800 MHz, and PCS 1900 MHz bands. Because of its small volume, the proposed antenna is a very attractive candidate for modern slim portable transceivers.