Resonant frequency and antenna pattern of a dielectrically filled, circular waveguide fed slot antenna

The effects of a dielectric filling material on the characteristics of a circular waveguide fed slot antenna are given. The antenna pattern is found using a sinusoidal aperture E-field distribution. The resonant frequency is found by using a theory for cavity backed slot antennas. The theoretical and experimental resonant frequency and antenna pattern of a dielectric-filled, circular waveguide fed slot antenna are presented. The error in resonant frequency was always less than 1% while the error in half-power beamwidth was less 2.61%. The good agreement between the theory and experiments implies that the main effect of the dielectric is in changing the propagation constant in the slot and not the slot aperture field distribution.<
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