Multi-physics Analysis of a Rasorber

The electromagnetic-thermal effects of a sandwich-structured rasorber for high-power microwave (HPM) systems is simulated and analyzed. Both of electromagnetic and thermal characteristics are obtained in the multi-field module of simulation software CST. The rasorber is configured by cascading a lossy layer above a lossless layer with an air to separate them, which has a −10 dB reflection reduction ranging from 5.4 to 14.8 GHz and a transmission window with an insertion loss of 0.34 dB at 10 GHz when the loss tangent of substrate material is fixed as 0 to achieve high-efficiency transmission. The temperature focuses mainly on the area where the electric field intensity is maximum for both lossy layer and lossless, and the peak temperature is greater in the former than in the latter. With the increase of slot width of Jerusalem cross-slot from 0.1 to 0.6 mm in the lossless layer, the stable temperature can drop from 144.2°C to 101.1°C. A novel phenomenon was found in the curves of the transient peak temperature versus time with the variation of incident angles under TE and TM polarization. This work provides a new insight for FSRs, indicting the potential possibility for conformal applications under modern high-power array antennas systems, which can be used for the evaluation between electromagnetic and thermal properties.