Radiation from a rectangular waveguide with a lossy flange

The radiation from a rectangular waveguide with a lossy flange coating is studied both analytically and experimentally. An analytic method using Fourier analysis and an impedance boundary condition is proposed. The experiment was performed using a flange covered with a rubber ferrite sheet at an X-band frequency. The numerical and measured results agree well and show that the lossy flange improves the E-plane radiation pattern and the crosspolar radiation. A boresight gain drop of about 2 db is predicted theoretically and measured experimentally.<
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