US 4,048,579 A · Feed-forward amplifier

Abstract

A feed-forward amplifier with an input arranged to receive wide-band signals and an output to supply a linearly amplified version of these has two parallel signal paths arranged between such input and output, one of the signal paths includes a cascade connection of a signal amplifier and a delay network and the second signal path includes an error amplifier, an error extraction circuit having a directional coupler in which an input side has a first pair of conjugate first and second ports and is connected partly to the input of the feed-forward amplifier and partly to an output of the signal amplifier and an output side has a second pair of conjugate third and fourth ports, the fourth port being connected to an input of the error amplifier, and an error injection circuit which has a first and a second input connected to an output of the delay network and to an output of the error amplifier, respectively and an output connected to the output of the feed-forward amplifier, the error extraction circuit having the third port of the directional coupler connected to an input of the signal amplifier and a summation circuit having a first and second input connected to the input of the feed-forward amplifier and to the output of the signal amplifier, respectively, and an output connected to the second port of the directional coupler.

Claims8

Dependent claims

A feed-forward amplifier for receiving an input signal and emitting an output signal comprising:

a main signal amplifier having an input port and an output port;
first signal processing means for forming a difference signal between the received input signal and the signal at the output port of said main signal amplifier;
dividing means for dividing the difference signal into first and second difference signal components and having first and second output ports for emitting the first and second difference signal components respectively;
first connecting means for connecting the first output port of said dividing means to the input port of said main signal amplifier whereby the first difference signal component is fed to said main signal amplifier;
and second signal processing means having first and second input ports and an output port for arithmetically combining the signals received at its input ports and emitting the result signal at its output port;
second connecting means for connecting the output of said main signal amplifier to the first input port of said second signal processing means;
and third connecting means for connecting the second output port of said dividing means to the second input port of said second signal processing means.

4 more elements

Dependencies are inferred from the claim text.

Feed-forward amplifier

Life of this patent

Feed-forward amplifier

Life of this patent

Abstract

Claims8