antenna element in the form of a rectangular waveguide comprises:
a) at least one slot situated in the center of one broad side,
b) a rectangular ridge arranged in the center of the interior surface of the other broad side, the slot and the ridge each extending along the longitudinal direction of the waveguide,
c) coupling devices, particularly a pin, arranged in the area of the slot, which excite the slot to emit electromagnetic energy, and
d) compensation devices constructed on the surface of the ridge facing the slot, which compensation devices compensate the mismatch of the waveguide caused by the coupling devices with respect to the generator feeding the waveguide with electromagnetic energy, the compensation devices being constructed such that the ridge has a step-shaped indentation in the area of thepositive.
The ridge on the broad side of the waveguide opposite the slot can also be represented as a capacitance in an equivalent circuit. As a result of the step-shaped indentation of the ridge according to the invention, the ridge size is reduced. This causes a lowering of the electric field energy relative to a full size ridge. The capacitance therefore has a negative value.
According to a preferred embodiment of the invention, the devices for exciting the emission of the waveguide wave are formed by a pin made of a conductive material arranged laterally next to the slot.
With respect to the longitudinal direction of the waveguide, the pin is preferably arranged at the level of the center of the slot.
In a preferred embodiment, the step-shaped indentation has a rectangular