Patent ID: 8072207
Filing Date: 2011-12-06
Classification: G01R

Abstract:
1. A device for measuring a frequency of an input signal that is expected to comprise a carrier signal either being unmodulated or being modulated according to a predefined signal coding, comprising: a reference clock counter for generating a measurement period which is adapted to count edges of a reference clock signal that has a constant reference frequency, wherein the measurement period is defined by the duration the reference clock counter needs to count from a predefined initial value to a predefined final value, wherein counting of the reference clock counter is temporarily halted when an absence of edges in the input signal is detected, an input signal counter being adapted to count edges of the input signal during the measurement period, sampling means for detecting whether the input signal contains edges, a controller being adapted to read a count value of the input signal counter on expiration of the measurement period and to derive the frequency of the input signal from the count value of the input signal counter, wherein the reference clock counter for generating the measurement period is adapted to extend the measurement period by a time period during which the absence of edges in the input signal is detected.