Rectangular waveguide loaded by a radiating slot

The design of phased arrays using open-ended waveguides requires the solution of singular integrodifferential equations, and the coupling between the higher modes of the guides leads to the blindness phenomenon. It is suggested that an array of rectangular waveguides loaded by radiating slots might be free of those problems. A rectangular guide loaded by a narrow slot is considered. The dominant-mode reflected wave and the fields of the evanescent modes generated by the magnetic current equivalent to the slot are obtained from explicit expressions previously reported. The measured and calculated values of the input resistance and reactance are plotted, showing fair agreement between theory and experiment. It is shown that the operational bandwidth of this radiator can be increased by a reactive stub.<>