Design of small and broad-band internal antennas for IMT-2000 mobile handsets

The objective of this paper is to design some small broad-band internal ant ennas for third-generation International Mobile Telecommunications-2000 (IM T-2000) mobile handsets. By introducing substrates of low dielectric consta nts and electromagnetically coupling two shorted microstrip patch elements, of either rectangular or semidisc shape, both compactness and broad bandwi dth can be achieved. These novel internal antennas for IMT-2000 mobile hand sets incorporate only one single probe feed in a driven patch element, whil e the broad-band feature is obtained by realizing dual-frequency operation. The typical impedance behavior and far-field radiation pattern characteris tics of eight different antenna configurations are discussed theoretically and experimentally.