Patent ID: 7847597

Claim:
A detector for detecting changes in a frequency of a frequency signal, the detector comprising, a splitter for splitting the frequency signals into a first undelayed signal and a second undelayed signal, a delay for delaying by a predetermined amount of a predetermined delay the second undelayed signal to produce a delayed signal, a mixer for mixing together the delayed signal and first undelayed signal for providing a mixed signal, the mixed signal changing over time as the frequency of the frequency signal changes over time, the frequency of the frequency signal has a predetermined center frequency, the frequency signal being V(t)=sine[2πf o t+φ(t)], the predetermined center frequency is f o , the predetermined delay is T equaling (2n−1)/4f o , n being an integer, and the delayed signal is Vd(t)=sine[2πf o (t−T)+φ(t−T)], and the delay comprises a coarse delay for 2n/4f o and fine delay for ¼f o .