A reconfigurable rat race coupler and methods of designing and reconfiguring the rat race coupler are disclosed. The reconfigurable rat race coupler, includes a plurality of transmission lines. The plurality of transmission lines include: a first transmission line and a second transmission line each of which comprise a phase shifter; and a third transmission line and a fourth transmission line each of which comprise phase shifters. A signal input on port 1 is provided between the phase shifters on the third transmission line, which is split between ports 2 and 3, with port 4 being isolated and port 2 being between the phase shifters on the fourth transmission line.