Silicon carbide/phosphate ceramics composite for electromagnetic shielding applications: Whiskers vs particles

We report on the design of highly absorptive thermostable composite materials for microwave applications. Ceramics comprising the thermostable phosphate host and silicon carbide particles or whiskers were studied in a wide frequency range from several Hertz up to microwaves. It was demonstrated that a thin layer of ceramics placed on the back-reflector absorbs perfectly at the 30 GHz frequency. In the case of a free-standing ceramic composite layer being 1 mm thick, it provides more than 50% of absorption.