DEVICE FOR THE DIGITAL GENERATION OF A FREQUENCY-MODULATED SIGNAL, AND RADIOFREQUENCY DEVICE COMPRISING SUCH A DIGITAL DEVICE

摘要

A digital device generating a frequency-modulated signal. The device comprises a programmable divider which divides the frequency fH of the clock by a variable integer N supplied by a control circuit. The output pulse signal of the frequency divider initiates the supplying of the next value of N by the control circuit. A shaping circuit brings the pulse signal into the form of a signal whose half-cycles successively have a duration equal to an integer multiple N of the clock period 1/fH. A supplementary circuit makes it possible to improve the precision of the modulation obtained compared with the desired phase by optionally delaying each half-cycle of the modulated signal by a fraction of the block period. The present invention is applicable to radar and telemetry.