Signal processor and method for processing a receiving signal

A signal processor for processing a receiving signal with a first usable frequency band and a second usable frequency band for obtaining two output signals, comprising:

• a first mixer for mixing the receiving signal with a first local oscillator signal, wherein a frequency of the first local oscillator signal is asymmetrical between the first usable frequency band and the second usable frequency band, and wherein the first mixer is implemented to acquire an in-phase signal and a quadrature signal with a first signal portion representing a mixed image of the first usable frequency band and with a second signal portion representing a mixed image of the second usable frequency band;
• and
• a second mixer for mixing the in-phase signal and the quadrature signal using a second local oscillator signal, wherein a frequency fLO2 of the second local oscillator signal is selected such that the mixed image of the first usable frequency band generated by the first mixer and the mixed image of the second usable frequency band generated by the first mixer are at least partly image bands of each other with regard to the second local oscillator signal,
• wherein the second mixer is implemented to separately provide information content of the first usable frequency band and the second usable frequency band at its output in order to acquire a first output signal, which substantially comprises information content of the first usable frequency band, and to acquire a second output signal, which substantially comprises information content of the second usable frequency band, and
• wherein, between a frequency f1 describing a band center of the first usable frequency band and a frequency f2 describing a band center of the second usable frequency band and the frequency fLO1 of the first local oscillator signal, one of the following relations holds:
• f2+0,15(f1−f2)≦fLO1≦f2+0,35(f1−f2)
• or
• f2+0,65(f1−f2)≦fLO1≦f2+0,85(f1−f2),
• wherein the frequency f2 is smaller than the frequency f1.

A signal processor for processing a receiving signal with a first usable frequency band and a second usable frequency band for obtaining two output signals, comprising:

• a first mixer for mixing the receiving signal with a first local oscillator signal, wherein a frequency of the first local oscillator signal is asymmetrical between the first usable frequency band and the second usable frequency band, and wherein the first mixer is implemented to acquire an in-phase signal and a quadrature signal with a first signal portion representing a mixed image of the first usable frequency band and with a second signal portion representing a mixed image of the second usable frequency band;
• and
• a second mixer for mixing the in-phase signal and the quadrature signal using a second local oscillator signal, wherein a frequency fLO2 of the second local oscillator signal is selected such that the mixed image of the first usable frequency band generated by the first mixer and the mixed image of the second usable frequency band generated by the first mixer are at least partly image bands of each other with regard to the second local oscillator signal,
• wherein the second mixer is implemented to separately provide information content of the first usable frequency band and the second usable frequency band at its output in order to acquire a first output signal, which substantially comprises information content of the first usable frequency band, and to acquire a second output signal, which substantially comprises information content of the second usable frequency band, and
• wherein a frequency f4 describes an upper band limit of the second usable frequency band, wherein a frequency f5 describes a lower band limit of the first usable frequency band, wherein a frequency f6 describes an upper band limit of the first usable frequency band, wherein, for a frequency fLO1 of the first local oscillator signal, the following two conditions are fulfilled:
• f4≦fLO1≦f5, and
• fLO1≧(f4+f6)/2;
• and
• wherein further the following holds:
• f4≦f5≦f6.

A signal processor for processing a receiving signal with a first usable frequency band and a second usable frequency band for obtaining two output signals, comprising:

• a first mixer for mixing the receiving signal with a first local oscillator signal, wherein a frequency of the first local oscillator signal is asymmetrical between the first usable frequency band and the second usable frequency band, and wherein the first mixer is implemented to acquire an in-phase signal and a quadrature signal with a first signal portion representing a mixed image of the first usable frequency band and with a second signal portion representing a mixed image of the second usable frequency band;
• and
• a second mixer for mixing the in-phase signal and the quadrature signal using a second local oscillator signal, wherein a frequency fLO2 of the second local oscillator signal is selected such that the mixed image of the first usable frequency band generated by the first mixer and the mixed image of the second usable frequency band generated by the first mixer are at least partly image bands of each other with regard to the second local oscillator signal,
• wherein the second mixer is implemented to separately provide information content of the first usable frequency band and the second usable frequency band at its output in order to acquire a first output signal, which substantially comprises information content of the first usable frequency band, and to acquire a second output signal, which substantially comprises information content of the second usable frequency band, and
• wherein the second mixer comprises a first mixer assembly, a second mixer assembly, a third mixer assembly, a fourth mixer assembly, a first combiner and a second combiner,
• wherein the first mixer assembly is implemented to receive the in-phase signal and a local oscillator signal associated to the first mixer assembly, and to generate an output signal associated to the first mixer assembly;
• wherein the second mixer assembly is implemented to receive the in-phase signal and a local oscillator signal associated to the second mixer assembly, and to generate an output signal associated to the second mixer assembly;
• wherein the third mixer assembly is implemented to receive the quadrature signal and a local oscillator signal associated to the third mixer assembly, and to generate an output signal associated to the third mixer assembly;
• wherein the fourth mixer assembly is implemented to receive the quadrature signal and a local oscillator signal associated to the fourth mixer assembly, and to generate an output signal associated to the fourth mixer assembly;
• wherein the first combiner is implemented to combine the output signal of the second mixer assembly with the output signal of the third mixer assembly for acquiring the first output signal;
• wherein the second combiner is implemented to combine the output signal of the first mixer assembly with the output signal of the fourth mixer assembly for acquiring the second output signal;
• wherein the local oscillator signals of the first mixer assembly and the third mixer assembly differ by 20 degrees at the most with regard to their phase position;
• wherein the local oscillator signals of the second mixer assembly and the fourth mixer assembly differ by 20 degrees at the most with regard to their phase position;
• and
• wherein the local oscillator signals of the first mixer assembly and the third mixer assembly comprise a phase shift in a range between 70 degrees and 110 degrees compared to the local oscillator signals of the second mixer assembly and the fourth mixer assembly.

A signal processor for processing a receiving signal with a first usable frequency band and a second usable frequency band for obtaining two output signals, comprising:

• a first mixer for mixing the receiving signal with a first local oscillator signal, wherein a frequency of the first local oscillator signal is asymmetrical between the first usable frequency band and the second usable frequency band, and wherein the first mixer is implemented to acquire an in-phase signal and a quadrature signal with a first signal portion representing a mixed image of the first usable frequency band and with a second signal portion representing a mixed image of the second usable frequency band;
• and
• a second mixer for mixing the in-phase signal and the quadrature signal using a second local oscillator signal, wherein a frequency fLO2 of the second local oscillator signal is selected such that the mixed image of the first usable frequency band generated by the first mixer and the mixed image of the second usable frequency band generated by the first mixer are at least partly image bands of each other with regard to the second local oscillator signal,
• wherein the second mixer is implemented to separately provide information content of the first usable frequency band and the second usable frequency band at its output in order to acquire a first output signal, which substantially comprises information content of the first usable frequency band, and to acquire a second output signal, which substantially comprises information content of the second usable frequency band,
• wherein the signal processor is implemented to sample the first output signal or a signal derived therefrom with a sampling frequency and to convert the same in an analog/digital manner for acquiring a first digitalized signal, and to sample the second output signal or a signal derived there from with the sampling frequency and to convert the same in an analog/digital manner for acquiring a second digitalized signal, and
• wherein the sampling frequency deviates by 20% at the most from a four-fold of a second intermediate frequency to which the second mixer images the image of the first usable frequency band and the image (of the second usable frequency band.