Photonic true time delay for high-frequency phased array systems

Pointing accuracy and sidelobe level control in wideband phased array radar antennas depend on the use of true time delays between the microwave elements. A photonic true time delay line based on an optical heterodyne system was previously introduced for beamformers operating in the hundreds of megahertz frequency range. We extend this concept to higher operating frequencies through the use of a dichromatic solid state laser, and present new insights into the nonlinearities found in this and previous data.<>