| 摘要 |
<p>This device comprises: - means of measuring a radiofrequency parameter of the filter (11), this parameter being a parameter characteristic of the misalignment of this filter relative to a setpoint time or frequency response, and - means for modifying the control of the said filter in a direction reducing this misalignment, these means being means servocontrolled in relation to the measurement of the said parameter. The said radiofrequency parameter can in particular be the input standing wave ratio of the filter, the transfer function or the impulse response of the filter, or even the distortion factor of the transmitted signal. In order to measure the radiofrequency parameter, it is in particular possible to apply to the filter a series of pure frequencies localised within the band over which the filter is to be controlled, and/or over the edges of this band, then to control the filter by minimising a function of deviation of the values of the radiofrequency parameter measured at the said pure frequencies relative to corresponding ideal stored values, and/or by symmetrising values of the radiofrequency parameter measured at the said pure frequencies relative to at least one given central frequency. <IMAGE></p> |
