Comments on "A wide-band simultaneous send-receive circuit for data cables"

Reply’ by H. Guckela If a transmission line of characteristic admittance YO is terminated at both ends with the circuit described in my letter,’ the transmission line may be used for simultaneous sending and receiving of arbitrary data. This transmission line is represented as a part of YR1 in both couplers. If the coupler circuit is designed as outlined’ and YE1 is realized as a matching network which provides YE’ = YO’ in one direction and also yields a total equivalent admittance YO in the other direction, the entire system, couplers and transmission line, will be flat: Le., no internal reflections will be generated. Thus in essence the circuit in my letter’ represents a directional coupler which is not frequency selective. Sun’s comment that the received signal does not involve transmission through the coupler is in error. The signal is incident at the