Patent ID: 7154347
Filing Date: 2006-12-26
Classification: H03C,H03L

Abstract:
1. A compensating method for a PLL circuit that functions according to the principle of two-point modulation, comprising: (a) injecting a first digital modulation signal into the PLL circuit, the PLL circuit being tuned to a first frequency, (b) injecting a second digital modulation signal into the PLL circuit, the PLL circuit being tuned to a second frequency, which is different from the first frequency, (c) coupling out a differential signal, which is characteristic of a change of a control signal of a frequency-generating unit of the PLL circuit that is brought about by the two digital modulation signals, (d) comparing the differential signal with a comparison signal, which is characteristic of a modulation amplitude of an analog modulation signal, and (e) changing the modulation amplitude in such a way that a deviation between the differential signal and the comparison signal that is determined in the comparison is eliminated.