High output amplifier with linearized circuit

Abstract

Abstract PURPOSE:To obtain a necessary high output from a small-scale high power amplifier(HPA) and to realize an unmanned earth station by by receiving the output signal of the 1st detector and the output signal of the 2nd detector and generating a voltage corresponding to the amplitude difference between both signals, and applying it as a control signal to a variable attenuator. CONSTITUTION:The vector modulators(V.M.) consisting of two components, i.e. a variable attenuator 7 and a phase shifter 9 are brought under negative feedback control and then one fine part signal 104 of the output of an HPA 1 which is led out by a coupler 2 is controlled to the same amplitude and phase with the output of a delay device 3. The delay device 3 compensates signal delay caused in the V.M. and HPA 1, but the V.M. and HPA 1 normally have a wide band, so the quantity of the delay is small. Thus, an output signal 103 becomes invariably in phase with an input signal 101 and the HPA 1 is linearized. For the purpose, the amplitudes and phases of the input and output signals of the HPA are detected directly, and distortion control is performed through a negative feedback loop on the basis of the result, so that accurate distortion corrections are made.

Inventors

• 👤 Osamu Ichiyoshi
• 👤 市吉　修

Bibliographic Details