Low-profile broadband planar antennas for DVB-H, DCS-1800, and IMT-2000 applications

A new type of low-profile broadband planar antenna is developed for DVB-H, DCS-1800, and IMT-2000 handsets. The planar antenna for UHF-band DVB-H terminals has a height of 8 mm while the antenna height for DCS-1800 and IMT-2000 applications is only 4.8 mm which is much lower than previously published antenna configurations. The broadband planar antennas consist of an S-strip and a folded T-strip which are separately printed on the two sides of a thin planar substrate. The bandwidth enhancement is realized by the mutual coupling between the S-strip and the T-strip. It has been demonstrated that the antenna for DVB-H terminals can achieve a gain of -2 to -4 dBi (3-7 dB higher than the standard specification) over the DVB-H band (470-702 MHz) while the antenna for the DCS-1800 and IMT-2000 handsets can achieve a bandwidth of-30% for return loss <-10 dB.