AUTOMATIC TUNING APPARATUS FOR A RESONATOR AND ITS APPLICATION WITHIN A SYNTHESIZER

摘要

1. Device for tuning a resonator (1) associated with a variable frequency oscillator, comprising a first device (2) and a second device (23, 12, 13, 14) for controlling the tuning frequency, the second being a mechanical device ; a device (7) for converting the oscillator frequency, comprising at least one divider having a variable divisor ; a control device (10) supplying a signal representative of the divisor to one input of the converter device (7) ; a phase comparator (3) receiving an alternating reference signal and a signal supplied by the oscillator frequency converter device (7) and supplying a slaving signal ; a low-pass filter (4) filtering this slaving signal and restituting a signal of the value Va , the first control device (2) continuously acting in dependence on this signal regardless whether the value Va is above or equal to a limit V1 and below or equal to a limit V4 , V4 exceeding V1 ; characterized in that the second control device (23, 12, 13, 14) is active if the value Va reaches the limit V1 , or the limit V4 , to restore the value Va to a value V2 strictly exceeding V1 , and to a value V3 strictly below V4 , respectively.