| 摘要 |
<p>An improved apparatus and method of generating swept frequency waveforms in the field of digital lineariser technology, using a phase-locked loop frequency synthesiser, is provided. Preferably, a ramp generator 120 is used to apply a modulation signal to the frequency control input of a voltage controlled oscillator via a summer component 110 . A direct digital synthesis (DDS) reference component 400 is used to controllably produce a progressive shift in threshold crossing points of the signal (on line 144 ) such as to compensate for the ramp signals generated by the generator 120 which is compared with the signal (on line 146 ) from the reference frequency source (line 140 ). Advantageously, the proposed apparatus/method finds utility in various FM CW-based radar applications.</p> |
