| 摘要 |
Wide bandwidth compensating circuits are disclosed for compensating for the nonlinearity of other circuits placed in cascade therewith over a relatively wide bandwidth, particularly for high linearity optical modulators, in which first and second versions of a signal are generated having different gains and different nonlinear distortions. The first signal has a higher gain with a lower distortion. The second signal has a lower gain with a higher distortion, and is subtracted from the first larger amplitude signal to form an output signal having a desired nonlinear transfer characteristic over a relatively wide frequency range. A first exemplary circuit has a first higher gain path and a second lower gain path having a transfer characteristic with a substantially greater amount of negative cubic distortion. The first and second signals are subtracted in a wide band differential amplifier to form a resultant signal having a desired positive cubic distortion. Second and third exemplary circuits are also disclosed.
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