Abstract: A broadband amplifier includes an amplifier device and input and output networks formed of microstrips. The impedance of the output microstrip is chosen by taking the geometric mean of the real parts of one of the scattering parameters of the amplifier device, at the lower and upper limits of the frequency range of interest, and by taking the geometric mean of the system impedance with the result obtained previously. The final result of these calculations is the impedance of the output network. The impedance of the input network is made to be at least twice, and preferably twice, the impedance of the output network. The amplifier is also provided with a slope compensation circuit. It has been discovered that an amplifier designed in this manner exhibits remarkable flatness over a five-octave range. The amplifier circuit is therefore suitable for use in cable television and other broadband telecommunications applications, where the frequency range of interest may be 30 MHz to 1000 MHz.

Abstract: A broadband amplifier includes an amplifier device and input and output networks formed of microstrips. The impedance of the output microstrip is chosen by taking the geometric mean of the real parts of one of the scattering parameters of the amplifier device, at the lower and upper limits of the frequency range of interest, and by taking the geometric mean of the system impedance with the result obtained previously. The final result of these calculations is the impedance of the output network. The impedance of the input network is made to be at least twice, and preferably twice, the impedance of the output network. The amplifier is also provided with a slope compensation circuit. It has been discovered that an amplifier designed in this manner exhibits remarkable flatness over a five-octave range. The amplifier circuit is therefore suitable for use in cable television and other broadband telecommunications applications, where the frequency range of interest may be 30 MHz to 1000 MHz.

Abstract: A filter for use in a cable television system for filtering out a given channel comprising a two pole filter, said filter including one pole which is fixed at the center frequency to be tuned out and a second variable pole responsive to an input voltage, the second pole adapted to vary in frequency about the first pole.The filter is employed in addressable control system which includes an address generator at a head end, generating address control signals for each of a plurality of remote subscribers, a modulator for modulating a carrier with the address and control signal and coupling it onto cables, circuits at receiving terminals for receiving and demodulating the modulated carrier to recover the address signals, address decoding means for each subscriber to decode the address and control signals and circuits responsive to the decoding means to select the channels which each subscriber will receive.