Design of a Triple-Band Planar Inverted-F Antenna For Cellular /PCS/ DMB applications

Due to the rapid development and widespread usage of various communication systems, multiband internal antennas are necessary for recent mobile handsets [1]-[3]. To meet the antenna requirement for hand-held terminal, the size reduction is one of the key requirements while maintaining the good multiband and wideband performance. Furthermore, a small intenna that can be integrated into the handset offers many advantages over the conventional external monopole or helical antennas. A potential candidate for such antennas is a planar inverted-F antenna (PIFA) [4]-[7]. However one of the principal disadvantages of basic PIFA elements is its narrow bandwidth of about 4 to 12% for return loss less than -10dB. In this paper, a triple-band PIFA is designed to operate at the center frequencies of 870 MHz, 1800 MHz and 2650 MHz. The introduction of a slant slot into the main patch generates three separate resonant modes for desired triple-band operation while the use of U-shaped patch is used for impedance matching PCS/DMB bands and size reduction. This antenna has enough bandwidth (≤ -10 dB) to cover the Cellular (824-894 MHz), PCS (Personal Communication Service, 1750-1870 MHz) and DMB (Digital Multimedia Broadcasting, 2605-2655 MHz) service at the same time.