At the present paper the available properties of the linear FM signal are summed up. And the transfer function of the compression network analogous to a matched filter is discussed. It is suggested that the program for the active pulse compression system can be accomplished by using a wire-type dispersive ultrasonic delay line. The experimental results of the active system are also given. Following the discussion of the principle for the passive pulse compression system

the practical program of the passive system used in the laboratory is introduced. The experimental results of the passive system are given. The research work on the active pulse compression system with the compression ratio of 100 and the passive one with that of 140 has succeeded. The compressed-pulse width of the former is 5μs

and that of the latter

3μs. The experimental results

agree with the theoretical estimations.