Down-converting multiple received radio frequency signals
First Claim
1. A circuit for producing a plurality of LO signals for down-converting a plurality of different RF signals operating in different frequency ranges, the circuit comprising:
- a VCO that produces a VCO output signal that serves as a first LO signal having a first frequency;
a first frequency translator that receives the VCO output signal and produces a second LO signal having a second frequency that differs from the first frequency; and
a second frequency translator that receives the VCO output signal and produces a third LO signal having a third frequency that differs from both the first frequency and the second frequency.
1 Assignment
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Accused Products
Abstract
A down-converting circuit for a multiple-band wireless communications device needs only one voltage-controlled (VCO) with a relatively narrow tuning range, and down-converts multiple different received RF signals to produce intermediate frequency (IF) signals having a common frequency. The VCO output signal serves as a first LO signal. The circuit also has up to two frequency translators, the first of which (e.g., a divide-by-2 translator) receives the VCO output signal and produces a second LO signal. The second frequency translator (e.g., a divide-by-1.5 frequency translator) also receives the VCO output signal and produces a third LO signal. The received RF signals are down-converted using the LO signals and mixers. One of the received RF signal types is a GPS signal, which is down-converted using an LO produced at the output of a divide-by-1.5 frequency translator.
29 Citations
48 Claims
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1. A circuit for producing a plurality of LO signals for down-converting a plurality of different RF signals operating in different frequency ranges, the circuit comprising:
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a VCO that produces a VCO output signal that serves as a first LO signal having a first frequency;
a first frequency translator that receives the VCO output signal and produces a second LO signal having a second frequency that differs from the first frequency; and
a second frequency translator that receives the VCO output signal and produces a third LO signal having a third frequency that differs from both the first frequency and the second frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A circuit for receiving a VCO output signal having a VCO frequency and using the VCO output signal for down-converting a plurality of different RF signals operating in different frequency ranges, the circuit comprising:
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a first mixer that receives a first RF signal, receives the VCO output signal as a first LO signal, and produces a first IF signal;
a first frequency translator that receives the VCO output signal and produces a second LO signal having a second frequency that differs from the first frequency;
a second mixer that receives a second RF signal and the second LO signal and produces a second IF signal;
a second frequency translator that receives the VCO output signal and produces a third LO signal having a third frequency that differs from the first frequency and from the second frequency; and
a third mixer that receives a third RF signal and the third LO signal and produces a third IF signal. - View Dependent Claims (20, 21, 22, 24, 25, 26, 27)
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23. The circuit of claim 23, wherein the VCO is capable of producing a VCO output signal with a frequency tunable within the range of about 2092 MHz to about 2170 MHz.
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28. A circuit for receiving a VCO output signal having a VCO frequency tunable within a range of about 2092 MHz to 2170 MHz and using the VCO output signal for down-converting a plurality of different RF signals operating in different frequency ranges, the circuit comprising:
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a first high-side mixer that receives a first RF signal having a frequency within a range of about 1930 to 1990 MHz, receives the VCO output signal as a first LO signal, and produces a first IF signal with a frequency of about 180 MHz;
a divide-by-2 frequency translator that receives the VCO output signal and produces a second LO signal having a second frequency that equals the frequency of the VCO signal divided by two;
a second high-side mixer that receives a second RF signal having a frequency within a range of about 869 MHz to 894 MHz, receives the second LO signal, and produces a second IF signal having a frequency of about 180 MHz;
a divide-by-1.5 frequency translator that receives the VCO output signal and produces a third LO signal having a third frequency that equals the frequency of the VCO signal divided by 1.5; and
a low-side mixer that receives a third RF signal having a frequency of about 1575 MHz, receives the third LO signal, and produces a third IF signal having a frequency of about 180 MHz. - View Dependent Claims (29, 30, 31, 32)
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33. A circuit for producing, in a wireless communications device, an LO signal for down-converting a GPS signal operating at about 1575 MHz to an IF signal, the circuit comprising:
a divide-by-1.5 frequency translator that receives a VCO output signal and produces the LO signal for down-converting the GPS signal to an IF signal. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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44. A circuit for producing, in a wireless communications device, multiple LO signals from a VCO signal for down-converting a plurality of different RF signals operating in different frequency ranges, the circuit comprising:
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a VCO that produces the VCO signal that serves as a first LO signal for down-converting an RF signal of a first type to an IF signal; and
a divide-by-1.5 frequency translator that receives the VCO signal and produces a second LO signal for down-converting a GPS RF signal operating at about 1575 MHz. - View Dependent Claims (45, 46, 47, 48)
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Specification