Electropolyaniline/carbonyl iron powder composite absorbing material

Conductive polymerConductive polyaniline/carbonyl iron powder composites were prepared based on the excellent electromagnetic wave absorption properties of soft magnetic metals In the experiment, conductive polyaniline was mixed with carbonyl iron powder in a ratio of 2:8 to form a composite powder, and then the composite powder was mixed with polyurea binder in a ratio of 2:8 to form an absorbing coating The test results show that when the conductivity of polyaniline is 10-2S/cm and the average particle size of carbonyl iron powder is 1-2 μ m, better absorption performance than -10 dB can be obtained in the frequency range of 2-12 GHz Analysis shows that this type of material is expected to develop into excellent absorbing materials with wide bandwidth, strong absorption, and special frequency bands that can be artificially designed

Conductive polymers and soft magnetic metal multi sided convex surfaces can meet the low-frequency (L, S band) stealth requirements, but like plasma stealth technology, they both have strong scattering directions, making it difficult to resist high-precision ground air integrated multi base detection on empty platforms,Microwave absorbing materialsCombining with a reasonable target shape is the best microwave stealth option, but the difficulty lies in the difficulty of achieving low-frequency thin layer absorbing materials Therefore, it is proposed to implement low-frequency-Thin layer absorbing materialThe new approach and comprehensive analysis research method is to express the interrelationships between the parameters related to the required absorbing materials from a systems theory perspective and numerical methods, and systematically point out the limitations and misconceptions caused by traditional design methods

Artificially synthesized materials with both negative dielectric constant (ε 0) and negative magnetic permeability (μ 0) have attracted widespread attention due to their unique electromagnetic properties such as negative refraction, inverse Doppler shift, inverse Cherenkov radiation, and enhancement of evanescent waves The preparation of various negative refractive index media structures and their applications in microwave engineering, military radar stealth, medical imaging, and other fields have been a research hotspot in recent years
This thesis is based on the research objective of the National Natural Science Foundation of China project "Synthesis Method and Characteristics Study of Controllable Tunable Negative Refractive Index Microwave Materials". It conducts in-depth research on the development, electromagnetic properties, and absorption applications of YIG metal line array structure negative refractive index media for ferromagnetic materials. The main research work and innovative achievements are as follows:
One Theoretical analysis, electromagnetic simulation, and physical experiments were combined to study the interaction relationship between two media in the negative refractive index medium of the YIG metal line array structure of ferromagnetic materials. The theoretical expression of effective medium parameters was analyzed, and the design and fabrication method of an improved YIG-PCB structure negative refractive index medium was proposed. The improved negative refractive index medium sample was processed The experimental test results show that the negative refractive index medium has a clear transmission passband at 9 GHz, with a 3 dB bandwidth of 0.5 GHz. The transmission passband can be changed with the change of the applied DC control magnetic field. When the applied DC magnetic field increases from 2300 Oe to 2700 Oe, the center frequency of the transmission passband increases from 8.42 GHz to 9.50 GHz.