Research On High-Isolation Passive Magnetoelectric Isolator In Ferrite/Piezoelectric Composites

The electrical isolation device/device provides the necessary signal isolation for the dual port network,eliminates the damage of surge to human body and automation equipment,and provides anti-jamming protection for precision instruments to ensure the isolation and inde-pendence of automation equipment.Traditional digital isolation technology realizes signal iso-lation through the integration of basic discrete components such as operational amplifiers,which is often poor in scalability and requires a separate power supply,which not only increases the volume of the device but also is not conducive to the miniaturization of the device.In view of the above,this paper takes Ni_0.8Zn_0.2Fe₂O₄/Pb Zr_0.48Ti_0.52O₃ ferrite/piezoelectric composite magnetoelectric samples as the research object,the non reciprocal characteristics around,dual port impedance measurement and isolation device testing and calibration of the following contents:（1）Study the relationship between capacitive/inductive dual-port imped-ance response characteristics and non-reciprocity of devices under low frequency response,ex-plore the realization principle of high isolation performance of devices,and further provide theoretical guidance for device design and construction.（2）Measure the amplitude-frequency response characteristics of the device to obtain the operating frequency range of the device.（3）In order to further improve the isolation performance of the device,further explore the influence of external bias magnetic field on the isolation degree of the device.The results show that:（1）The device transfer impedance of Z₁₂ and Z₂₁ is approximately equal and opposite in phase（211Ωand 198Ω,respectively）,and the input/output impedance of Z₁₁ and Z₂₂ is about 10³ orders of magnitude different（60.83Ωand 23.38 kΩ,respectively）.The results show that significant port impedance difference is helpful to achieve higher isolation under non-reciprocal characteristics.（2）The working frequency range of the device measured by the impedance analyzer is 56.65-56.82 k Hz,and the isolation degree of the device Z₂₂/Z₁₁=402 under the excitation of resonant state f=56.73 k Hz.（3）When H=190 Oe,the device isolation is as high as 1220,which improves the isolation performance about 3 times compared with the response when H=0.Therefore,the proposed magnetoelectric non-reciprocity device has the advantages of passivity,high integration（strong scalability）,miniaturization and so on.It not only provides a new design idea for the development of new electrical isolation devices,but also further expands the application field of magnetoelectric functional devices under low frequency excitation,especially in the field of automatic control.It has positive potential appli-cation value for high/low voltage isolation and signal isolation between controller and actuator.