Ninety degree phase stepper

摘要

A 90 degree phase stepper is described comprising a tandem array of one 90 degree hybrid coupler and one 180 degree hybrid coupler. A phase shifter, capable of introducing either zero or 180 degrees of phase shift, is included in each of the two wavepaths connecting the two couplers. By the appropriate selection of phase shifts, the phase of the output signal can be continuously increased or decreased in 90 degree or 180 degree increments.