A coupling device includes a plurality of couplers, a first coupled output port and a second coupled output port, wherein the plurality of couplers comprise a first coupler and a second coupler that are adjacent one another, and each of the first coupler and the second coupler comprises a main line and a subline, and for each of the first coupler and the second coupler: the subline includes a first section, a second section, and a third section, wherein the second section of the subline of the first coupler has a common segment with the first section of the subline of the second coupler.