COMPACT BROAD-BAND 5-BIT PHOTONIC TRUE-TIME-DELAY MODULE FOR PHASED-ARRAY ANTENNAS

Photonic true-time-delay (TTD) lines offer many advantages over their electronic counterparts and are attracting more and more research effo rt. We demonstrate a device with 32 TTD lines (5-bit) based on substra te guided-wave propagation combined with slanted photopolymer volume p hase gratings on a quartz substrate. System design, device fabrication , optimization of fan-out intensity uniformity, and device performance evaluation are addressed as well. The device has a measured bandwidth of up to 2.4 THz and a measured fan-out delay step of 50 ps. The fan- out beam intensity uniformity is within +/-10%. The packing density is 2.5 delay lines/cm(2), which is to our knowledge the highest demonstr ated thus far. (C) 1998 Optical Society of America.