FM band multiple signal modulator
First Claim
1. Apparatus for generating a set of carriers that are equally spaced in frequency across a band, comprising in combination:
- first means for generating a waveform that has a spectrum which consists substantially of only odd integer multiples of a frequency equal to half the spacing between the carriers in the band;
second means for generating a sinusoidal signal having a frequency equal to the center frequency of the band;
a mixer having a first input terminal connected to said first means for receiving the waveform, having a second input terminal connected to said second means for receiving the sinusoidal signal, and having an output terminal, said mixer producing in response to the waveform and to the sinusoidal signal an output signal that includes the set of carriers on said output terminal.
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Accused Products
Abstract
Apparatus and a method for generating all of the assignable carrier frequencies in the FM broadcast band and for frequency modulating the generated carriers includes a generator of a train of pulses having a crystal-controlled repetition frequency and a specific pulse shape which together produce a spectrum of odd harmonics of the pulse repetition frequency whose separation in frequency is identical to that of the assignable carrier frequencies. This pulse train is then mixed with a 98.0 MHz sine wave to translate the spectrum to the FM band. Simultaneous modulation of all the carriers is achieved by frequency modulating the 98.0 MHz sine wave, whereby the same modulation is imparted simultaneously to all of the carriers.
109 Citations
29 Claims
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1. Apparatus for generating a set of carriers that are equally spaced in frequency across a band, comprising in combination:
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first means for generating a waveform that has a spectrum which consists substantially of only odd integer multiples of a frequency equal to half the spacing between the carriers in the band; second means for generating a sinusoidal signal having a frequency equal to the center frequency of the band; a mixer having a first input terminal connected to said first means for receiving the waveform, having a second input terminal connected to said second means for receiving the sinusoidal signal, and having an output terminal, said mixer producing in response to the waveform and to the sinusoidal signal an output signal that includes the set of carriers on said output terminal. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of generating a set of carriers that are equally spaced in frequency across a band, comprising the steps of:
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a) generating a waveform that has a spectrum which consists substantially of only odd integer multiples of a frequency equal to half the spacing between the carriers in the band; b) applying the waveform as a first input to a mixer; and
,c) applying as a second input to the mixer a sinusoidal signal having a frequency equal to the center frequency of the band, whereby the set of carriers is present in the output signal of the mixer. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. Apparatus for generating a set of carriers that are equally spaced in frequency across a band and for simultaneously frequency modulating the carriers with an applied modulating signal, said apparatus comprising in combination:
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first means for generating a waveform that has a spectrum which consists substantially of only odd integer multiples of a frequency equal to half the spacing between the carriers in the band; second means for producing a frequency modulated signal in response to an applied modulating signal, the frequency modulated signal having a carrier frequency equal to the center frequency of the band; a mixer having a first input terminal connected to said first means for receiving the waveform, having a second input terminal connected to said second means for receiving the frequency modulated signal, and having an output terminal, said mixer producing in response to the waveform and to the frequency modulated signal an output signal that includes the set of carriers each frequency modulated by the applied modulating signal, the output signal being presented on the output terminal of said mixer. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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22. A method of generating a set of carriers that are equally spaced in frequency across a band and for simultaneously frequency modulating the carriers with an applied modulating signal, said method comprising the steps of:
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a) generating a waveform that has a spectrum which consists substantially of only odd integer multiples of a frequency equal to half the spacing between the carriers in the band; b) applying the waveform as a first input to a mixer; and
,c) applying as a second input to the mixer a frequency modulated signal having a carrier frequency equal to the center frequency of the band, whereby the set of frequency modulated carriers is present in the output signal of the mixer. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29)
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Specification