A small meander antenna by magneto-dielectric material

Nowadays, new digital multimedia broadcasting services like DVB-H and DABAT-DMB (terrestrial digital multimedia broadcasting) have been realized through VHF/UHF band and provides large opportunities for mobile business. The antenna size for DVB-H and DAB/T-DMB must be too large to be assembled in mobile equipments because a quarter wavelength of VHF band in vacuum (/spl mu//sub r/=1, /spl epsi//sub r/=1) is about 40 cm. To solve this problem, we have developed new small antennas consist of meander conductive metal pattern and magneto-dielectric (/spl mu//sub r/>1, /spl epsi//sub r/>1) layers. The ferrite resin composite material and ferrite film have been used for magneto-dielectric layers. The results of electromagnetic field simulation showed that resonant length of an antenna must be 1//spl radic/(/spl mu//sub r/X /spl epsi//sub r/), and the resonance frequency of a magneto-dielectric antenna was about 30-50% of an antenna by dielectric material. And, small volume thin film magneto-dielectric material nearby antenna conductive pattern might be able to shorten wavelength without serious radiation problem.