Abstract: A hybrid coupler is disclosed. The hybrid coupler comprises a printed circuit board having a first metallization layer and a second metallization layer arranged below the first metallization layer. The first metallization layer comprises at least two input ports and at least two output ports. The hybrid coupler further comprises a plurality of couplers coupled adjacent to each other on the first metallization layer. Each coupler of the plurality of couplers comprises transmission traces electrically coupled with the transmission traces of an adjacent coupler and the transmission traces of the plurality of couplers extend between the input ports and the output ports of the first metallization layer. The hybrid coupler furthermore comprises a defective ground structure having a pre-defined shape defined in the second metallization layer below each coupling junction formed between the transmission traces of the plurality of couplers.

Abstract: A base station antenna includes a calibration circuit that has a plurality of pairs of directional couplers and an antenna array that includes a plurality of columns of radiating elements. The first polarization radiators of the radiating elements in each column are electrically connected to a first directional coupler of a respective one of the pairs, and the second polarization radiators of the radiating elements in the column are electrically connected to a second directional coupler of the respective one of the pairs. The directional couplers may be arranged in a manner that reduces in-column coupling and/or that reduces cross-column coupling between adjacent columns of radiating elements.