The invention relates to a directional coupler comprising coupled lines, and a method for achieving coupling in a directional coupler under compensation conditions. The directional coupler comprises coupled lines (8, 9), including a first line (8) and a second line (9), and at least one ground plane (10, 11, 13). At least one of the ground planes is a tuning ground plane (10, 11, 13), and a distance (14, 25), between the first (8) and the second (9) line, and each distance (15, 17, 26, 27), between the first line (8) and the respective tuning ground plane (10, 11, 13), are adapted so as to contribute to a desired coupling level under compensation conditions.