Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1805320 | Journal of Magnetism and Magnetic Materials | 2006 | 5 Pages |
Abstract
In order to apply to a novel, flexible type of GHz noise suppressors, we prepared Ni0.2ZnxFe2.8âxO4 films with x=0.3 and 0.6 and thicknesses of 2 and 5 μm, by spin spray ferrite plating from an aqueous solution on polyimide sheets at 90 °C. Placing the films onto a microstrip line, we measured transmission loss ÎPloss and reflection parameter S11 at 10 MHz-10 GHz. As x increased from 0.3 to 0.6, fr (natural resonance frequency) decreased from 350 to 50 MHz, which resulted in decreasing fc (a frequency from which ÎPloss begins rising) from 400 to 100 MHz. This means we can tune fc of the films by changing the Zn concentration x. At 8 GHz, ÎPloss obtained by the ferrite films increased from 40% to 70% when their thickness increased from 2 to 5 μm. We obtained S11<10%, irrespective of Zn concentration, in the whole measurement frequency range. By the films with x=0.3 and 2 μm thickness we obtained ÎPloss=40%, which was as strong as that obtained by a commercially available composite sheet type noise suppressor of 25 μm thickness that are made of ferromagnetic metal flakes embedded in a flexible polymer matrix. Moreover, ÎPloss by the ferrite film increased to 70% when the thickness was increased to 5 μm. Therefore, our NiZn ferrite films are promising to be actually used as GHz noise suppressors with tunable working frequencies that exhibit stronger noise suppression than the commercialized composite type of noise suppressors.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Koichi Kondo, Tatsuya Chiba, Hiroshi Ono, Shigeyoshi Yoshida, Yutaka Shimada, Nobuhiro Matsushita, Masanori Abe,