Broadband predistorsion linearizer

1/ A broadband predistorsion linearizer of gain and phase for a power amplifier operating in the microwave range, the linearizer having means for conferring gain and phase predistorsion which compensate the gain and phase non-linearities of the corresponding amplifier, said linearizer further comprising:

• an inlet splitter having one inlet and two outlets;
• a “linear” first path and a “non-linear” second path, said linear and non-linear paths presenting, by construction, the same group propagation times;
• an outlet combiner having two inlets and one outlet;
• said non-linear path having a broadband non-linear element comprising a Lange coupler, each of its two accesses being grounded via respective active elements;
• and
• said linear path comprising a Lange coupler identical to that of the non-linear path, each of its two accesses being grounded via a respective passive element;
• the linearizer being characterized in that said two passive elements are open-circuit segments of microwave transmission line (“stubs”) of adjustable length, the length serving to adjust relative phase between the linear and non-linear paths in constant manner over the entire frequency band, thus performing the function of a phase shifter, and in that at least one of said linear paths and said non-linear path (preferably the linear path) includes at least one etched resistor in series or parallel with the transmission line and acting as an attenuator of value that is adjustable between a finite value and zero by short-circuiting the resistor with a foil or at least a metal wire.