A New Magneto-Dielectric Material Loaded, Tunable UHF Antenna for Handheld Devices

Experimental determination of magnetocrystalline anisotropy constants and saturation magnetostriction constants of NiZn and NiZnCo ferrites intended to be used for antennas miniaturization

“…The magnetic phase of this porous nanostructured material is constituted by nanograins of ferrite. Such low loss materials can be obtained by applying moderate temperature to the material after compaction [21][22][23][24][25][26]. Actually, it is the key to benefit by ferrites properties at higher frequencies that to use them as half-massive -instead of full massive -ceramics.…”

“…Domain wall contribution to the permeability is avoided when the magnetic particles remain small enough to stand in a single domain state, which allows the material to be used at higher frequencies than a bulkier one. The ability of these materials to reduce antenna dimensions in the application frequency range of 400 À862 MHz has been demonstrated [21,26], and small antennas have been realized [11,[22][23][24][25].…”

Optimization of Ni0.95−xZnxCo0.05Fe1.90Mn0.02O4 ceramics with promising magneto-dielectric properties for VHF antenna miniaturization

“…However, while physical dimensions of the antennas are decreased, their electrical performances should not be compromised. 3,4 Antenna miniaturization can be made by using materials with high dielectric permittivity. [1][2][3][4] One issue regarding the use of high permittivity materials would be presence of highly localized electric field near by, thus leading to significant reduction in antenna efficiency and narrowed band performances.…”

“…3,4 Antenna miniaturization can be made by using materials with high dielectric permittivity. [1][2][3][4] One issue regarding the use of high permittivity materials would be presence of highly localized electric field near by, thus leading to significant reduction in antenna efficiency and narrowed band performances. Meanwhile, a large mismatch in impedance was generated, due to the application of the high permittivity materials, which tremendously damaged the matching requirement for antenna designs.…”

Compact Antennas — An overview

“…• Folded configurations [8][9][10] • Surface etching techniques [11][12][13][14] • Shorting walls or pins [15][16] • The use of high dielectric constant materials or magneto-dielectric materials [17][18][19][20][21][22].…”