| 摘要 |
A method of linearizing a modulator (1) having two parallel-coupled sub-modulators (2, 3). The complete transmission function of the modulator includes parameters which relate to power division (A, 1-A) of a non-modulated carrier wave (Pin) and a relationship (B) between the activation degree of the sub-modulators (2, 3). The transmission function is simplified and series-expanded with two higher-order terms, each having a respective coefficient. An expression for intermodulation distortion is calculated with the aid of the series-expansion and with control signals (V1, V2) having two or three frequencies. The signs of the coefficients are determined so that the terms having these coefficients will mutually counteract their respective distortion contributions, and limited search regions for the parameters (A, B) are calculated with the aid of the sign-determined coefficients. In accordance with secondary conditions for high electrooptic efficiency and pronounced modulation depth, the distortion level of the modulator is calculated with the aid of the complete transmission function in the search regions.
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