HYBRID ELECTRONIC FIBER OPTIC WAVELENGTH-MULTIPLEXED SYSTEM FOR TRUE TIME-DELAY STEERING OF PHASED-ARRAY ANTENNAS

A hybrid electronic fiber optic true time-delay steering architecture is presented which retains the highly hardware compressive property of an earlier all-optical approach and introduces the economical advantages of electronics at every level possible without compromising overall performance. The architecture is particularly suited to large arrays where maximum advantage can be taken of the hardware compression. A detailed design based on this architecture is described for steering a linear, 16-element, L-band (0.7- to 1.4-GHz) array in transmit mode over a scan angle of +/- 20 deg with a delay resolution of 6 bits (0.63 deg). An analysis of the expected performance of the design is given together with progress toward the fabrication of the prototype system, which includes the first iteration electronic binary delay line subsystem and a single-segment, high-fidelity, directly modulated DFB laser diode fiber optic link. The experimental data from these modules is in agreement with the performance predicted from the analysis.