an asymmetrical distortion of the field distribution in the waveguide under the slot. In the equivalent circuit diagram, the slot-pin combination acts like a shunt-connected capacitor in parallel to a series-resonant circuit. For the compensation of the capacitor, an inductive diaphragm can be used in waveguide technique. However, its implementation is difficult in practice and furthermore itself causes a field distortion counterproductive to the excitation of the emission.
It is an advantage of the invention to provide an improved slot antenna element.
According to the invention, this advantage is achieved by providing a slot antenna element in the form of a rectangular waveguide. The slot antenna element includes at least one slot situated in the center of one broad side, a rectangular ridge arranged in the center of the interiorsurface of the other broad side. The slot and the ridge each extend along the longitudinal direction of the waveguide. A coupling device, particularly in the form of a pin, is arranged in the area of the slot, which excites the slot to emit electromagnetic energy, and a compensation device is constructed on the surface of the ridge facing the slot, which compensation device compensates the mismatch of the waveguide caused by the coupling device with respect to the generator feeding the waveguide with electromagnetic energy. The compensation device is constructed such that the ridge has a step-shaped indentation in the area of the slot. Advantageous further developments of the slot antenna element according to the invention are the object of dependent claims.
According to the invention, the slot