LAUSR

Considering the difficulty in measuring the P-band electromagnetic parameters of porous materials such as graphene foam (GF), this paper proposes a free-space frequency-domain technology to measure the electrical properties of finite-plate materials from multiple perspectives. First, the multiangle reflectance of the sample was measured with the arch method; second, an electromagnetic simulation model consistent with the sample size was established, and the reflectance of different angles was calculated using the method of moments (MoM). Finally, the genetic algorithm (GA) was optimized for the electromagnetic parameters such that the reflective difference between the electromagnetic simulation model and the test obtained was minimized. The validity of the method was verified by reconstructing the electromagnetic parameters of a 1 $\text{m}\times 1\,\,\text{m}\times 0.03$ m absorbing material at 0.5 GHz. The unique advantage of this method is that it solves the problem of inversion of electromagnetic parameters based on the multiangle reflectivity of an absorbing material plate within three times the wavelength. Because the electromagnetic simulation model can automatically divide the appropriate mesh size according to the size of the electromagnetic parameters, this method is suitable for high-loss and low-loss materials. In addition, this method avoids the special processing requirements regarding the shape size of the absorbing material, which has a wide application scope and low cost.