Broadband photonic microwave phase shifters with amplitude and phase controls

A new photonic microwave phase shifter structure that can realise multiple continuous 0 to 360 degree phase shifts with independent control, is presented. It is based on controlling the amplitude and phase of the optical carrier and two anti-phase RF modulation sidebands of the wavelength division multiplexed phase modulated optical signals. The new photonic microwave phase shifter also has the ability to control the output microwave signal amplitude. It has the advantages of high frequency and wide bandwidth operation, and a simple structure. Experimental results are presented that verify the new concept.