A Compact Dual-band Planar Antenna Loaded with Magneto Dielectric Ferrite

In this paper, a compact dual-band planar antenna loaded with magnetodielectric ferrite is proposed for ISM/GSM/UMTS. Slot and ring structures are dual-resonant mode generators of the antenna. And the characteristic mode analysis is used for the modeling, analysis, and optimization of the proposed antenna. Because of the loading of a piece of rectangular Co2W hexaferrite medium, this antenna can be used in lower frequency bands. The electromagnetic parameters of this ferrite are measured by the transmission line method. Finally, the antenna is fabricated and measured. The operation frequency band (S11<-10 dB) is determined to be 80 MHz (890-970 MHz) and 370 MHz (1.87-2.24 GHz) with the dual resonance frequencies of 925 MHz and 2.175 GHz, respectively, which is capable for ISM (915 MHz)/GSM900/UMTS applications.