Join date: May 15, 2022


Replay Ken Grimwood.epub




The field of the invention is electronic controllers, and particularly the control of the transmission of signals from central stations to remote stations. It is known that in communications systems, the signals carried by the transmission lines from a central station to a remote station have a variety of problems associated therewith, and it is therefore desirable to provide some type of signal regenerating or equalizing circuit. In microwave communication systems, it is known that the transmission lines which connect the central station to the remote stations can be of the coaxial or balanced type. In the balanced transmission line, equal and opposite voltages occur at the two ends of the line. A simple regenerating circuit can be provided to take the signal that occurs on a transmission line and re-generate the signal that would normally be transmitted on the line. However, the regenerating circuit must do so at the same frequency that occurs on the transmission line. As the bandwidth of the signal is now the same as the bandwidth of the transmission line, it is not possible to achieve any type of channel equalization. As the bandwidth of the transmission line is much greater than the channel equalization requirement, the signal regenerating circuit is used primarily for its signal equalization capability, with a minor modification to the signal appearing on the transmission line being considered to be a separate channel for the purpose of the regenerating circuit. The signal regenerating circuit for a balanced transmission line is shown in FIG. 1. It is known in the art that the input signal Vin (line ground shown) is present on one side of the device and an equal and opposite voltage is present at the other side. These voltages are created by the voltage induced on the line at the ground reference point. The regenerating circuit includes a differential amplifier circuit with the reference point at the amplifier inputs, and provides an output equal to the signal on the transmission line. This circuit is well known in the art. However, for regeneration purposes, it is necessary to include a peak detector. A peak detector is a circuit which determines the maximum signal amplitude of the input signal, and then provides a signal to the differential amplifier which is the difference between the signal peak amplitude and the mean amplitude of the input signal. An example of the type of peak detector circuit used in this application is shown in FIG. 2. It consists of a differential amplifier with an input stage composed of two NPN transistors Q1 and Q2 which are connected to a power supply circuit. Q1 and Q2 are connected at the base of each other,





Replay Ken Grimwood.epub

More actions