Overview
RF Foam Absorber: (Include Flat absorber and Pyramidal absorber)
Principle of Operation:
Pyramidal absorbers are based on the principle of tapered impedance. By steadily increasing the impedance from that of "free space" at the incident surface of the absorber to a high impedance, lossy material at the rear surface, energy is progressively absorbed and attenuated through ohmic loss as it propagates through the absorber.
Flat absorber provides approximately 20dB of absorption over the design range, which is dependent on thickness: 0.25 inch absorber works from 18GHz up while 9.0 inch absorber works from 400MHz up. Although the flat-faced design makes this absorber flexible, lightweight and inexpensive, performance is limited to 20dB because of the higher front-face reflections.
