Microwave photonic phase shifter based on a nonreciprocal optical phase shifter inside a Sagnac interferometer

A new microwave photonic phase shifter is presented. It is based on an optical single-sideband modulator and an optical phase shifter inside a Sagnac interferometer. It relies on the use of the novel nonreciprocal optical phase shifter to obtain an optical phase shift, which converts into an RF phase shift. The microwave photonic phase shifter has the advantages of realising a continuous 0-360 degrees phase shift on microwave signals using off-the-shelf components and only requiring a single control It also has a compact structure and robust performance. Experimental results are presented, which demonstrate 0-360 degrees phase shift of microwave signals over a sub-octave frequency band. (C) 2014 Elsevier B.V. All rights reserved.