Communication semiconductor integrated circuit device and a wireless communication system
First Claim
1. A semiconductor integrated circuit device for communication use, said device comprising:
- an oscillation circuit for generating an oscillation signal with a frequency pursuant to an externally set value;
a first frequency division circuit for frequency division of the oscillation signal as generated by said oscillation circuit to thereby generate a signal of intermediate frequency;
a modulation circuit for modulating the signal as frequency-divided by said first frequency division circuit;
a first frequency conversion circuit for converting a signal modulated by said modulation circuit into a transmission signal with higher frequency; and
a second frequency conversion circuit for combining together a signal taken out of the output side of said first frequency conversion circuit and a signal as frequency-divided by a second frequency division circuit to thereby generate a signal with its frequency equivalent to a frequency difference between these signals, said first frequency conversion circuit being arranged to form a transmission signal based on the signal converted by said second frequency conversion circuit and the signal modulated by said modulation circuit, wherein said oscillation circuit includes an oscillator, a programmable frequency divider capable of frequency-dividing an oscillation signal of the oscillator in accordance with a frequency division ratio supplied thereto, a phase comparator for detection of a phase difference between an output signal of the programmable frequency divider and a reference signal, and frequency control means for outputting a voltage or a current pursuant to the phase difference detected by said phase comparator and for controlling the oscillation frequency of said oscillator, and said device comprises a frequency division ratio generation circuit for generating an integer part I and a fraction part F/G based on band information concerning an externally supplied use frequency band and mode information indicative of whether signal transmission or reception and channel information as to a setup frequency, and for generating the frequency division ratio based on said integer part I and fraction part F/G.
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Accused Products
Abstract
In a communication semiconductor integrated circuit device using offset PLL architectures and including an oscillator circuit and a frequency divider circuit generating an intermediate frequency signal, the oscillator circuit includes an oscillator, a programmable frequency divider which frequency-divides the oscillation signal in accordance with frequency division information, a phase comparator detecting a phase difference between an output signal of the programmable frequency divider and a reference signal, and a frequency control unit for outputting a signal indicative of the phase difference and controlling the oscillation frequency of the oscillator, wherein a frequency division ratio generator circuit generates an integer part I and a fraction part F/G based on band information concerning the use frequency band and mode information along with channel information and for producing the frequency division ratio information to thereby give it to the programmable frequency divider.
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Citations
14 Claims
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1. A semiconductor integrated circuit device for communication use, said device comprising:
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an oscillation circuit for generating an oscillation signal with a frequency pursuant to an externally set value;
a first frequency division circuit for frequency division of the oscillation signal as generated by said oscillation circuit to thereby generate a signal of intermediate frequency;
a modulation circuit for modulating the signal as frequency-divided by said first frequency division circuit;
a first frequency conversion circuit for converting a signal modulated by said modulation circuit into a transmission signal with higher frequency; and
a second frequency conversion circuit for combining together a signal taken out of the output side of said first frequency conversion circuit and a signal as frequency-divided by a second frequency division circuit to thereby generate a signal with its frequency equivalent to a frequency difference between these signals, said first frequency conversion circuit being arranged to form a transmission signal based on the signal converted by said second frequency conversion circuit and the signal modulated by said modulation circuit, wherein said oscillation circuit includes an oscillator, a programmable frequency divider capable of frequency-dividing an oscillation signal of the oscillator in accordance with a frequency division ratio supplied thereto, a phase comparator for detection of a phase difference between an output signal of the programmable frequency divider and a reference signal, and frequency control means for outputting a voltage or a current pursuant to the phase difference detected by said phase comparator and for controlling the oscillation frequency of said oscillator, and said device comprises a frequency division ratio generation circuit for generating an integer part I and a fraction part F/G based on band information concerning an externally supplied use frequency band and mode information indicative of whether signal transmission or reception and channel information as to a setup frequency, and for generating the frequency division ratio based on said integer part I and fraction part F/G. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification