Design of a variable S-band fiber-optic delay line

This paper describes the design of a variable S-band delay line based on fiber-optic technology. A combination of a switched-RF configuration and switched-fiber configuration has resulted in improved performance with reduced costs compared to previously reported delay line systems. The reported delay line provides variable delays programmable from 0 nsecs to 9.55 /spl mu/secs in 50 nsec increments and may be switched as quickly as 600 nsecs. The delay line achieved a worst case output noise floor <-55 dBm/MHz, an output SNR>60 dB/MHz with the input signal at the 1 dB compression level of 6.6 dBm, a gain linearity