Control of Non-Linear Permeability of Ferrite Composite Materials in High Frequency - Application to Integrated Ferrite Antenna -

对锰锌铁氧体、镍锌铁氧体及其复合材料的高频非线性磁导率进行了研究。研究了磁场对它们的影响。结果表明：(1)在Mn-Zn铁氧体中，在100kHz以上的频率范围内，由于畴壁振动导致复磁导率出现共振型频散；由于磁畴壁的减少，烧结铁氧体的色散型转变为弛豫型。在复合材料中，渗透率色散发生在100MHz以上。在谐振区外磁场的作用下色散特性发生了变化。(2)在Ni-Zn铁氧体中，烧结体在几MHz以上出现松弛型自然共振。在复合材料中，由于粒子中的退磁场，频率色散向高达几GHz的方向移动。(3)采用烧结镍锌铁氧体连接两条带状线的带状线结构，研究了高达1GHz的电磁波参数放大。电磁波的传输可以通过共振区域的外场来控制，但不能实现放大。因此，提出了用铁氧体连接两个谐振腔的新结构。

Investigations for high frequency non-linear permeability of Mn-Zn ferrte, Ni-Zn ferrtei and their composite materials have been carried out. Magnetic field effect to them were also studied.Results are as follows,(1) In Mn-Zn ferrite, resonance type frequency dispersion of complex permeability due to domain wall vibration has been observed in the frequency above seceral 100kHz. Dispersion type change to relaxation in sintered ferrite due to the decrease of magnetic domain walls. In composite materials, permeability dispersion occurs over 100MHz. Dispersion character changes by application of external magnetic field in resonance region.(2) In Ni-Zn ferrite, relaxation type natural resonance has been observed above several MHz in sintered body. In composite materials, frequency dispersion shifts toward up to several GHz due to demagnetizing field in particles.(3) Parametric amplification of electromagnetic wave up to 1GHz was studied by the strip line configuration in which two strip lines were connected by sintered Ni-Zn ferrite. Transmission of electromagnetic wave can be controlled by the external field in resonance region, but amplification could not achieved. Thus new configuration, which combine two resonator connected each other by ferrite, were introduced.