| 摘要 |
A pulse compression radar which transmits a step-wise FM pulse and correlates at the receiver using a bank of delay lines (having progressively increasing delays) of the fiber optic type. One such delay line corresponds to each step of the frequency modulation program transmitted. The summed delay line outputs converted to electrical signals are summed to provide the compression desired. A suitably amplified stair-step received echo signal is applied to control the deflection of a Bragg cell illuminated from a laser source, the variable light ray deflection produced by the Bragg cell being focused progressively at the input of each of the discrete fiber optic delay lines. The same bank of fiber optic delay lines is employed in an oscillator loop, these delay lines being effectively electronically switched into place sequentially in the frequency determining feedback loop of the oscillator circuit. The same or a different laser source floods all inputs of the fiber optic delay lines through a light modulator in the feedback path, the desired stair-step FM transmitted signal being a modulation on the light energy employed in the oscillator configuration. Time-sharing transmit/receive and light source wavelength/color separation embodiments are shown.
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