Title :
Miniaturized T-DMB Antenna With a Low–Loss Ni–Mn–Co Ferrite for Mobile Handset Applications
Author :
Jeong Keun Ji ; Won Ki Ahn ; Jun Sig Kum ; Sang Hoon Park ; Gi Ho Kim ; Won Mo Seong
Author_Institution :
R&D Center, E.M.W. Antenna Co., Ltd., Seoul, South Korea
fDate :
7/2/1905 12:00:00 AM
Abstract :
In this paper, a low-loss Ni-Mn-Co ferrite (Ni0.76Mn0.24-xCoxFe2O4 with x = 0-0.04) has been developed for miniaturization and performance improvement of mobile handset antennas. The developed ferrite material has almost equal permittivity and permeability of 7-9, as well as sufficiently low dielectric and magnetic loss tangent less than 0.001 and 0.01 below 200 MHz, respectively. Miniaturization factor of about 8 and normalized impedance of about 1 were obtained at 200 MHz. A helical antenna operating at terrestrial digital multimedia broadcasting (T-DMB, 174-216 MHz) band was fabricated on the ferrite substrate, which has compact size, low loss, wide bandwidth, and good radiation performance.
Keywords :
cobalt alloys; ferrites; helical antennas; manganese alloys; mobile handsets; nickel alloys; radio broadcasting; Ni-Mn-Co; T-DMB antenna; dielectric loss; ferrite material; frequency 174 MHz to 216 MHz; frequency 200 MHz; helical antenna; magnetic loss; mobile handset antennas; permeability; permittivity; terrestrial digital multimedia broadcasting; Dielectric losses; Dielectric materials; Dielectric substrates; Ferrites; Iron; Magnetic materials; Mobile antennas; Mobile handsets; Permeability; Permittivity; Soft magnetic materials; antenna; ferrite; magnetic loss; magnetodielectric; terrestrial digital multimedia broadcasting (T-DMB);
Journal_Title :
Magnetics Letters, IEEE
DOI :
10.1109/LMAG.2009.2038580
