Multichannel predistortion linearizer for multiple amplifiers with

Abstract

The peaking of multiple input signals applied to the inputs of two or more distinct amplifiers, and the resultant intermodulation, can be reduced, or avoided, by: a) dividing each of the input signals into components from which the original input signals can be reconstructed, e.g., by using a Butler matrix of order greater than 2.times.2; b) developing a specially constructed signal which is likewise divided into components; c)supplying a component of each of the input signals and a component of the specially constructed signal to at least one of the amplifiers; and d) constructing amplified versions of the original input signals from the outputs of the amplifiers, e.g., by using another identical Butler matrix. The specially constructed signal is generated so as to reduce: 1) peaking at the one of amplifiers whose input signal peaking results in the highest peak during a particular time period; and 2) intermodulation in the output signals. The input signals may each be a modulated carrier signal and each of the amplified versions of the original input signals is supplied to a different antenna for transmission. The specially constructed signal can range over the entire bandwidth of the signals being amplified while the amplified version of it may be discarded, e.g., not supplied to any antenna.