摘要 |
Apparatus (1) for generating a control signal for a tunable circuit (3) sensitive to temperature receives an input control signal and predistorts it in a distortion circuit (4), so that the output (5) of the tunable circuit (3) will be substantially corrected for non-linearities in the tunable circuit (3). The distortion circuit (4) includes a linear non-distortion circuit element (9), which may be a linear temperature compensation element, and one or more non-linear distortion circuit elements (12, 13, 14), each of which distort the input control signal according to a different function. The outputs of the distortion circuit elements are passed to variable gain elements (17, 18, 19, 20) to produce weighted components. The weighted linear and non-linear components are then combined in a combination circuit element (8) to provide a predistorted control signal to the tunable circuit (3). <IMAGE> |