Novel Photonic True-Time-Delay Line Networks for Phased Array Antennas

The objective of this work is to develop photonic true time delay lines for broadband phased array antennas. The work will concentrate on two special architectures: the chirped fiber grating-tunable laser delay line, and the on-wafer all polymer binary delay line. Depending on the specific system requirements including the number of elements, operation frequency, and angular resolution, each architecture can offer certain advantages to the system performance. The first architecture uses the recent advances in the linearly chirped fiber Bragg grating fabrication and various tunable laser technologies. The second approach uses polymeric switches and modulators in a binary configuration with monolithic on-wafer all waveguide delay lines. Both approaches can lead to compact, low insertion loss, microprocessor directly controlled unit with phase and amplitude control. The nonlinear optical polymers provide devices with large electro-optic coefficients, large modulation bandwidth, fast switching time, and greater fabrication flexibility at lower cost, compared with LiNbO3 or GaAs waveguide technology. A prototype switch will be constructed and tested for a feasibility demonstration of the use of advanced nonlinear polymer materials for optical switching and signal processing during an option task to Phase 1.