An all-optical photonic microwave phase shifter that can realize a continuous 0°-360° phase shift is presented. The phase-shifting operation is implemented by controlling the phase of the two RF phase-modulation sidebands while keeping the optical carrier phase fixed. The use of two RF modulation sidebands, instead of a single sideband used in most conventional phase shifters, has the advantage of highoutput RF signal power, and consequently high signal-tonoise ratio performance. Experimental results demonstrate the full -180° to -180° phase shift over a wide microwave frequency range from 11 to 26.5 GHz, and 14 dB increase in the output RF signal power compared to a conventional phase shifter. © 2015 Optical Society of America.