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US 6,636,731 B1Granted
Demodulation method preserving a high spectral purity
AssigneeKoninklijke Philips Electronics N.V.
InventorNigel Greer
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Abstract
The invention relates to a method of demodulating a signal (I, Q) that has a main component and harmonics. According to the invetion, this method includes the following of a selection of one of the harmonics, and a demodulation of the selected harmonic. The invention enables the elimination of a parasitic component introduced by the demodulation into the demodulated signal SD without altering the data carried by the signal SD.
Claims6
A method of operating a receiver, said method comprising:
- receiving and transforming an electromagnetic signal into a radio frequency signal;
- converting the radio frequency signal into an intermediate frequency signal having a square-wave shape, the intermediate frequency signal including a main component and at least one harmonic;
- filtering the intermediate frequency signal through a bandpass filter having a center frequency corresponding to a first harmonic of the at least one harmonic;
- and
- demodulating the filtered intermediate frequency signal to yield a demodulated signal.
2 more elements
A demodulation device, comprising:
- a bandpass filter for filtering an intermediate frequency signal having a square-wave shape, the intermediate frequency signal including a main component and at least one harmonic wherein said bandpass filter has a center frequency corresponding to a first harmonic of the at least one harmonic, and
- a demodulator for demodulating the filtered intermediate frequency to yield a demodulated signal.
A receiver, comprising:
- an antenna system for receiving and transforming an electromagnetic signal into a radio frequency signal;
- a frequency conversion device for converting the radio frequency signal into an intermediate frequency signal having a square-wave shape, the intermediate frequency signal including a main component and at least one harmonic;
- and
- a demodulation device including
- a bandpass filter for filtering the intermediate frequency signal, said bandpass filter having a center frequency corresponding to a first harmonic of the at least one harmonic, and
- a demodulator for demodulating the filtered intermediate frequency signal to yield a demodulated signal.
3 more elements
Dependencies are inferred from the claim text.