A beamwidth modified model for calculation of reflected level of quiet zone in anechoic chamber

In calculation of reflected level of quiet zone in anechoic chamber, a spot emission model is often used to simulate antennas' characteristic. The model is useful in low frequency and not in microwave frequency because microwave antennas are of sharper directivity. In this paper, a new emission model, which can be used in microwave frequency, has been derived from Fresnel-Kirchhoff diffraction formulation. It has been demonstrated that new model is more appropriate to actualities than spot model.