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US 2003/0190901 A1Published application
Direct conversion receiving unit
AssigneeAsahi Kasei Microsystems Co., Ltd.
InventorsShinji Miya, Yuro Yoshizawa
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AssigneeAsahi Kasei Microsystems Co., Ltd.
InventorsShinji Miya, Yuro Yoshizawa
Estimating the term…
A direct conversion receiving unit includes an oscillation circuit (50) whose oscillation frequency fvco is (N/(N+1))×fR, where fR is a receiving frequency. The output of the oscillation circuit (50) is divided into two parts, one of which is converted to the frequency of (1/(N+1))×fR by a divide-by-N circuit (52). Mixing the two frequencies (1/(N+1))×fR and fvco=(N/(N+1))×fR generates the frequency fR, which is supplied to conversion mixers (38 and 44) as a local input. The receiving unit requires only one oscillation circuit, and excludes all the circuits that handle a frequency higher than fR, enabling a small size and low current consumption configuration.
A direct conversion receiving unit for receiving a received signal with a receiving frequency fR, said receiving unit comprising:
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Backward citations are indexed for grants only.
Demodulation of angle-, frequency- or phase- modulated oscillations: by converting the oscillations into two quadrature related signals
Circuits: for homodyne or synchrodyne receivers
Demodulation or transference of modulation from one carrier to another
Transmission
Term end not estimated
This application claims priority from Japanese Patent Application No. 2002-105440 filed Apr. 8, 2002, which is incorporated herewith by reference.
1. Field of the Invention
The present invention relates to a receiving unit used in a radio communication system, and particularly to a direct conversion receiving unit that converts a radio frequency signal to a baseband signal by a single conversion mixer.
FIG. 1 is a block diagram showing a configuration of a conventionally known direct conversion receiving unit;
FIG. 2 is a block diagram showing a configuration of a conventionally known superheterodyne receiving unit;
FIG. 3 is a block diagram showing a configuration of a direct conversion receiving unit with an oscillation circuit that directly generates the receiving frequency;
The invention will now be described with reference to the accompanying drawings.
Embodiment 1
FIG. 7 shows a configuration of the direct conversion receiving unit in accordance with the present invention.