FM TRANSMITTER
First Claim
1. An FM transmitter comprising:
- an oscillator connected with a crystal oscillator;
a clock generating circuit which generates a clock signal synchronized with a signal formed by frequency-dividing an output signal of the oscillator;
a digital signal processor to which the clock signal generated by the clock generating circuit is inputted as an operating clock, and which performs a stereo modulating operation to stereo data by digital processing; and
a carrier wave generating circuit to which a signal formed by frequency-dividing the output signal of the oscillator is inputted, and which generates a carrier wave synchronized with the inputted signal and having a frequency of an integer multiple of the frequency of the inputted signal, the FM transmitter transmitting an FM modulation signal formed by frequency-modulating a stereo composite signal obtained by the stereo modulating operation performed by the digital signal processor.
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0 Petitions
Accused Products
Abstract
An object of the present invention is to provide an FM transmitter in which the degree of freedom in parts selection is improved. The FM transmitter comprises: an oscillator 72 connected with a crystal oscillator 70; a clock generating circuit 50 which uses a signal formed by frequency-dividing an output signal of the oscillator 72 as a reference frequency signal fr1, and which generates a clock signal having a frequency of an integer multiple of the frequency of the reference frequency signal fr1; a DSP 20 which operates synchronously with the clock signal to perform stereo modulation processing, FM modulation processing, and IQ modulation processing to inputted stereo data by digital processing; a frequency synthesizer 60 which uses a signal formed by frequency-dividing the output signal of the oscillator 72 as a reference frequency signal fr2, and which generates a signal having a frequency of an integer multiple of the frequency of the reference frequency signal fr2; mixers 40 and 42 which mix signals outputted from the DSP 20 with signals generated by the frequency synthesizer 60, respectively; an adder 44 which adds outputs of the mixers 40 and 42; and an amplifier 46 which amplifies an output signal of the adder 44 and transmits the amplified signal from an antenna 48.
10 Citations
25 Claims
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1. An FM transmitter comprising:
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an oscillator connected with a crystal oscillator;
a clock generating circuit which generates a clock signal synchronized with a signal formed by frequency-dividing an output signal of the oscillator;
a digital signal processor to which the clock signal generated by the clock generating circuit is inputted as an operating clock, and which performs a stereo modulating operation to stereo data by digital processing; and
a carrier wave generating circuit to which a signal formed by frequency-dividing the output signal of the oscillator is inputted, and which generates a carrier wave synchronized with the inputted signal and having a frequency of an integer multiple of the frequency of the inputted signal, the FM transmitter transmitting an FM modulation signal formed by frequency-modulating a stereo composite signal obtained by the stereo modulating operation performed by the digital signal processor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. An FM transmitter comprising:
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an oscillator connected with a crystal oscillator;
a clock generating circuit which generates a clock signal synchronized with a signal formed by frequency-dividing an output signal of the oscillator;
a digital signal processor to which the clock signal generated by the clock generating circuit is inputted as an operating clock, and which performs a stereo modulating operation to stereo data by digital processing; and
a carrier wave generating circuit to which the output signal of the oscillator is directly inputted, and which generates a carrier wave that is synchronized with the output signal and that has a frequency of an integer multiple of the frequency of the output signal, the FM transmitter transmitting an FM modulation signal formed by frequency-modulating a stereo composite signal obtained by the stereo modulating operation performed by the digital signal processor. - View Dependent Claims (21, 22)
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23. An FM transmitter comprising:
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an oscillator connected with a crystal oscillator;
a clock generating circuit which generates a clock signal synchronized with an output signal of the oscillator;
a digital signal processor to which the clock signal generated by the clock generating circuit is inputted as an operating clock, and which performs a stereo modulating operation to stereo data by digital processing; and
a carrier wave generating circuit to which a signal formed by frequency-dividing the output signal of the oscillator is inputted, and which generates a carrier wave synchronized with the inputted signal and having a frequency of an integer multiple of the frequency of the inputted signal, the FM transmitter transmitting an FM modulation signal formed by frequency-modulating a stereo composite signal obtained by the stereo modulating operation performed by the digital signal processor. - View Dependent Claims (24, 25)
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Specification