Fully compact anechoic chamber using the pyramidal ferrite absorber for immunity test

A new generation of electromagnetic wave absorber, which has a pyramidal shape and 10 cm in height and excellent absorbing characteristics, was developed to satisfy the required characteristics of a fully compact anechoic chamber in the wide frequency range. The material of the new absorber is composed of a ferrite powder and polypropylene. When the new absorber was cascaded on a conventional ferrite absorber, the absorbing characteristics of this hybrid absorber was over 20 dB in the wide frequency range of 70 MHz to 10 GHz. At the same time, an anechoic chamber using the hybrid absorber presented excellent uniformity of electromagnetic field strength according as IEC 61000-4-3 in the frequency range of 26 MHz to 3 GHz.