Abstract: An active predistorting linearizer with agile bypass circuit for safe mode operation is used in conjunction with an amplifier. This linearizer comprises a controllable input variable-attenuator and drive-amplifier circuit supplied with the input signal to attenuate and amplify the input signal. A predistorter includes a controllable phase-shifting and amplitude-adjusting path supplied with the attenuated and amplified input signal to distort the latter signal and produce a predistorted output signal. A controllable output variable-attenuator and drive-amplifier circuit is supplied with the predistorted output signal to attenuate and amplify this predistorted output signal before supplying it to the power amplifier. A phase-shifting and amplitude-adjusting controller is connected to the controllable input variable-attenuator and drive-amplifier circuit, the controllable phase-shifting and amplitude-adjusting path, and the controllable output variable-attenuator and drive-amplifier circuit.