Patent ID: 6788139
Filing Date: 2004-09-07
Classification: H03F

Abstract:
A broadband pre-distortion-linearizer of gain and phase for a power amplifier operating in the microwave range, the linearizer having means for conferring gain and phase pre-distortion-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 first Lange coupler with two accesses, wherein each of its respective two accesses are grounded via respective active elements; and said linear path comprising a second Lange coupler identical to the first Lanae coupler, wherein each of its respective two accesses beifig are grounded via a respective passive element; wherein said two passive elements are open-circuit segments of microwave transmission line of adjustable length, the length serving to adjust a relative phase between the linear and non-linear paths in constant manner over the entire frequency band, and operable to perform the function of a phase shifter, and wherein further at least one of said linear path and said non-linear path includes at least one etched resistor in series with or parallel with the transmission line and acting as an attenuator having a value that is adjustable between a finite value and zero by short-circuiting the resistor with a foil or a metal wire.