The Study Of Characteristics Of Magnetic Thin Film Using For RF Noise Suppression

Electromagnetic compatibility (EMC) as a new comprehensive discipline is being more and more attention. Nowadays researches about Electromagnetic compatibility and resistance to Electromagnetic interference are actively carrying out in many countries, which involve circuit, materials, electronic device, and other fields, and with widely applications. As the Integrated circuit is getting smaller and smaller, with the frequency of signal is higher and higher, Improving the electromagnetic compatibility of integrated circuits is becoming increasingly important. Enhance anti-electromagnetic interference of the integrated circuit is the key to raise its electromagnetic compatibility. Some research reports indicated that noise suppressors using ferromagnetic films have widely application prospects in microwave integrated circuits and high-speed digital integrated circuits.In this paper we introduced the conception, meaning and application of the anti- electromagnetic interference and electromagnetic compatibility. Showed the main research methods and results of the current international magnetic thin film RF noise suppressors. Studied the absorption principle of magnetic films and the theory which support magnetic films can be used as a noise suppressor. Designed the microstrip line and coplanar line with the characteristic impedance of 50 ohm, and done the error analysis. We also introduced how to use network analyzer to measure the signal attenuation (S21), and developed a software to collect the data of the network analyzer. Finally, we analyze the signal attenuation on the transmission line with different ingredients and the size of the film, summed up various factors need to be considered when the magnetic films using as noise suppressor, and showed the prospect of the noise suppression device applications.This paper focused on the research of the attenuation characteristics on the transmission line with magnetic film. Discussed the impact of signal attenuation factors and the magnetic film as RF noise suppressor's methods and fields of application.According to this paper, the frequency and intensity of the signal attenuation on transmission line are mainly depended on the ferromagnetic resonance frequency and eddy current loss. Ferromagnetic resonance frequency change might lead to signal attenuation peak frequency corresponding change. Increasing the eddy-current losses will not change the frequency of attenuation peak, but will increase the intensity of attenuation. By changing the film size can change the ferromagnetic resonance frequency and eddy current loss, and achieve the maximal attenuation to the noise with specific frequency .