An Anechoic chamber is to be designed of a length of 10 meters for operating over a frequency range of 500 MHz to 40 GHz. Assume that Electromagnetic waves travel with speed of light inside the chamber. Explain and find the range of frequencies for which the chamber’s length can be considered as lumped or distributed circuit.
Very important is the size of absorption elements (such as pyramids ) on the wall constructions. In any case, they should be smaller than 0.1 of wavelength and has a reflection level smaller then -40 dB.
For a chamber to be considered a lumped element, the length generally should not exceed 0.1*lambda as Vadym Slyusar mentioned. This means the phase change from one point to another in the chamber can be neglected. For any length higher than 0.1*lambda the phase change is important and so the chamber must be considered as a distributed circuit.
Based on the length of your chamber (10 m), the transition wavelength is 0.1*10 = 1 m, which has a frequency of 300 MHz. For a range from 500 MHz to 40 GHz it seems to me that the chamber must be treated as a distributed circuit for the entire range.
This looks like a tutorial assignment problem and is one of the things Researchgate is not supposed to be used for, according to its terms and conditions.
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