Effect of the circular microstructure on absorbing properties of carbonyl iron rubber radar absorbing patch

A kind of radar absorber is designed and produced based on circular microstructure, which is composed of a circular microstructure, carbonyl iron rubber radar absorbing patch and metal backboard composition. Numerical simulation of effect of the circular microstructure on absorbing properties of carbonyl iron rubber radar absorbing patch is performed by means of the time domain finite integral method. Simulated results indicate that by using the holding absorber with the unchanged thickness of 2.5 mm, when the absorber unit size was P = 30 mm and the circular radius was R = 5 mm, the value of the minimum absorption peak can reach −43 dB, −10 dB absorption band shifted from 5.8–9.3 to 4.6–8.2 GHz, changing the parameters of circular microstructure greatly, expanding the absorbing bandwidth of microwave absorbing patch, reducing the reflectivity of resonance frequency. According to the simulation results, the samples are prepared and tested. The test results are in agreement with the simulation results.