A two-layer dielectric absorber covering a wide frequency range

A two-layer dielectric absorber for use as high temperature radar wave-absorbing material was developed by hot-pressing nanometer SiC and LAS glass-ceramic. The complex permittivity of the hot-pressed LAS glass-ceramic and SiC/LAS composite was investigated at 8.2–12.4 GHz. Results show that the real and imaginary parts of the permittivities of the SiC/LAS composites greatly increase as the content of the nanometer SiC powders increases. Based on the test results, a two-layer ceramic absorber, composed of LAS layer and SiC/LAS layer, covering a wide frequency range was designed and prepared. Its reflectivity at 8.2–12.4 GHz is less than −6 dB.