Super slim multiband inverted-F antenna for GSM/DCS/PCS operation

This paper presents the design of a super slim multiband wrapped inverted-F antenna that covers the frequency bands allocated for GSM, DCS and PCS wireless services. In the first step, the quarter-wavelength size (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 × 10 × 3 mm. Full wave EM simulations show that the antenna excites a lower mode resonance at about 850 MHz and a higher one at about 1900MHz. Its radiation pattern is nearly omni-directional with a gain of about 2.5dBi at the lower band and 4.6dBi at the upper band. A prototype of the proposed antenna is fabricated and tested. A close agreement between simulated and measured result is achieved. The measured 6-dB return loss or VSWR 3:1 bandwidths for the lower and upper resonances are 200MHz (770 to 970 MHz) and 280MHz (1710 to 1990 MHz) respectively. These bandwidths are sufficient to cover GSM 850/900/1800/1900MHz, DCS 1800MHz and PCS 1900MHz bands. Because of its compact volume the proposed antenna is a very attractive candidate for modern slim size portable transceivers.