Annular directional coupler, in particular for microwave-based distance sensors

摘要

An annual directional coupler having at least three taps, which are each arranged relative to one another around routes having a wavelength difference of ¼ of a wave guide wavelength, includes in particular at least two branch lines, wherein a first branch line has at least three taps and wherein the at least second branch line does not have any taps and is supplemented by an additional route corresponding to the wave guide wavelength.