A rigorous theory of electromechanical delay lines

Introduction of some insignificant restrictions into the theory of electromechanical delay lines gives rigorous solutions of great simplicity. These restrictions are: (a) the line shall be described by a two-row two-line matrix; (b) the transducers are represented by equivalent circuits with concentrated elements; (c) the transducers shall be electrically tuned to obtain the widest possible bandwidth; (d) the delay line shall be symmetrical; (e) the losses shall be restricted to the electromechanical transducer resonators, their mechanical terminating resistors and the electrical input and output circuits. The solution of the equations obtained solves an optimization problem and allows, among other things, the determination of the ripple W of the transfer at the band-edge as a function of the normalized attenuation in the middle of the pass-band.