Fill-level meter

A radar based, fill level measuring device for measuring a fill level of a fill substance in a container, comprising:

• a securement means by which the fill level measuring device is securable at a lateral opening of the container;
• a transmitting and receiving unit designed to;
• produce a radar signal and transmit the radar signal toward the fill substance;
• receive a reflected radar signal after reflection of the radar signal on a fill substance surface;
• and
• determine the fill level based on the received radar signal;
• and
• a tubular antenna arrangement having a defined tube axis, wherein the tubular antenna arrangement has a cross-section smaller than the lateral opening of the container, and wherein the tubular antenna arrangement has:
• an end region which, in a secured state, protrudes out into the container,
• a radar-bundling means arranged in the end region and oriented in the secured state perpendicularly to the fill substance, and
• a primary radiator connected with the transmitting and receiving unit and arranged in an interior of the tubular antenna arrangement in a focal point of the radar-bundling means to transmit the radar signal to the fill substance and to receive its reflection,
• wherein the radar-bundling means and the primary radiator each has an asymmetric aperture that is larger in parallel with the tube axis than orthogonally to the tube axis and
• wherein the radar-bundling means and the primary radiator are adapted to one another such that the primary radiator illuminates an outer contour of the radar-bundling means with the radar signal with less than −10 dB.