Design of a programmable 2-18 GHz microwave fiber-optic delay line

Describes the design of a programmable 2-18 GHz microwave delay line based on fiber-optic technology. The delay line achieves any delay from 0 to 658.54 μsecs programmable in 20 nsec steps. A combination of a switched-RF configuration and a switched-fiber configuration has resulted in delay performance not previously possible, The reported delay line is presently being constructed under a Phase II SBIR award from the Army Research Laboratory. The delay line achieves a worst-case SNR of 56 dB/1 Mhz and dBc of -37 dB with 0 dBm input signal level, SNR of 46.5 dB/1 Mhz and dBc of -46.5 dB with -9.5 dBm input signal level, 2-18 GHz bandwidth with gain linearity of ± 3 dB, infinite capture time, physical path switch time on the order of 30 nsecs, and power dissipation < 200 watts,