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US 2001/0041546 A1Published application
Direct-conversion modulation with reduced local oscillator leakage
OwnerLeonid Kazakevichinventor
Life of this patent
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Abstract
For direct up- or down-conversion between baseband and carrier frequency signals, each component of such a signal is supplied to a first mixer together with a local oscillator signal at one-half the carrier frequency and the output from that first mixer is supplied to a second mixer together with the same local oscillator signal, but at a phase which differs by 90° from that of the local oscillator signal supplied to the first mixer.
Claims11
A system for direct frequency conversion between baseband data signals and carrier frequency signals modulated with said baseband data signals, said system comprising:
- first and second mixers;
- means for supplying to one of said mixers the signals to be converted and a signal at one-half of said carrier frequency;
- means for supplying to the other of said mixers the output signal from said first mixer and said signal at one-half said carrier frequency, but with a phase which is in quadrature with said one-half frequency signal supplied to said first mixer;
- and
- said carrier frequency signals and said signals at one-half said carrier frequency being maintained in a predetermined phase relationship.
2 more elements
Dependencies are inferred from the claim text.