Fundamental examination about cooling approach for a heated EM-wave absorber under high power injection

Utilization of electromagnetic absorbers under high power is increasing to estimate performance of high power radars in anechoic chambers. Variation of absorption characteristics of absorbers is expected due to the generation of heat or temperature change. To suppress temperature increase, the absorber has to be cooled down in some kind of way. For example, the means are sending air to the absorber, loading radiating fin on the absorber, developing lattice structure in the absorber to increase heat transfer, and so on. In this paper, for the fundamental examination, the wind-chill factor by sending air to a heated lambda/4 EM-absorber is evaluated by measuring the temperature distribution with and without air blasting. As a result, the maximum temperature 78[degC] is confirmed on the surface of the absorber without air blasting. Meanwhile the maximum temperature decreases to 70[degC] on the surface of the absorber with air blasting. Therefore, the wind-chill factor by the air blasting is verified.