Microwave Power Absorption Characteristics of Ferrites

作者：Peng Zhiwei; Hwang Jiann Yang^*; Andriese Matthew

来源：IEEE Transactions on Magnetics, 2013, 49(3): 1163-1166.

DOI：10.1109/TMAG.2012.2227775

• Dielectric loss
• ferrites
• magnetic loss
• microwave absorbers
• resonance

The microwave power absorption characteristics of five ferrites, BaFe12O19, SrFe12O19, CuFe2O4, CuZnFe4O4 and NiZnFe4O4, have been studied by determining the average power absorption patterns of the ferrite slabs using the derived power equations with consideration of both microwave dielectric and magnetic losses. It is shown that microwave power dissipates rapidly in the ferrites with a thickness of microwave penetration depth D-p. The magnetic loss Q(H,av) is much larger than the dielectric loss Q(E,av) for these ferrites in the slab thickness range of 0-3D(p). The ratio of Q(H,av) to Q(E,av) remains above 1.5 as the slab thickness varies from D-p/4 to 3D(p) although the difference between losses decreases with increasing thickness. The power absorption patterns of these ferrites also demonstrate that microwave resonance caused by magnetic loss occurs within the materials having a thickness less than a half-wavelength in the medium lambda(m)/2. It is anticipated that microwave magnetic field heating of ferrites with a thickness smaller than lambda(m)/2 can be accelerated by magnetic loss resonance which leads to a significant increase in the power absorption in these ferrites.

• 出版日期2013-3