Patent ID: 7099016

Claim:
Method for analyzing a spectrum of an input signal (x(t)) having at least one line with a center frequency (ω x ) at the center of the line comprising the following steps: zero-mixing the input signal (x(t)) to produce a base band signal (z(t)) by sweeping a local oscillator frequency (ω s ), —filtering the base band signal (z(t) ) with a resolution filter to produce a filtered base band signal (y(t)), —reconstructing the envelope (E(ω)) of the spectrum of the input signal (x(t)) by using an estimated amplitude (ŷ x ) at an estimated center frequency ({circumflex over (ω)} x ) of each line of the input signal (x(t)), whereby the estimated amplitude (ŷ x ) and the estimated center frequency ({circumflex over (ω)} x ) are calculated from the time of occurrence (t i ), the duration (ΔT i ) and the maximum value (y′ i ) of at least one evaluated halfwave of the filtered base band signal (y(t)).