Dual-mode transmitter
First Claim
1. A transmitter, comprising:
- a multi-signal generator for simultaneously providing a plurality of signals within a portion of a selected frequency band and having a center frequency and relative frequency spacing of said simultaneous plurality of signals, wherein said multi-signal generator is a variable multi-signal generator for selectively adjusting said center frequency to cause said plurality of signals to cover a differing of the selected frequency band;
a modulator connected to said multi-signal generator for selectively and simultaneously modulating said plurality of signals;
a control unit for selectively controlling said multi-signal generator center frequency;
a decoder adapted to prevent a transmission of said plurality of signals in response to receipt of an emergency transmission.
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Accused Products
Abstract
An emergency and non-emergency transmitter receivable by broadcast band receivers in nearby vehicles, comprising a first signal generator for simultaneously providing a plurality of selectively spaced carriers having frequency spacings corresponding to the individual channels of the band to be covered and selectively providing amplitude modulation when used for the AM broadcast band, and a second signal generator providing an FM modulated signal, which when combined with the signal from the first signal generator, covers various portions of the FM broadcast band to provide complete coverage thereof. A plurality of signals are generated in a portion of a selected band and modulated, according to the selected band mode, with a pre-stored and selectable voice alarm message. An EAS/RDS decoder monitors for emergency transmissions and deactivates the dual-mode transmitter if an EAS/RDS transmission is detected so that radios within the coverage area of the dual-mode transmitter will receive the EAS/RDS transmission.
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Citations
22 Claims
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1. A transmitter, comprising:
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a multi-signal generator for simultaneously providing a plurality of signals within a portion of a selected frequency band and having a center frequency and relative frequency spacing of said simultaneous plurality of signals, wherein said multi-signal generator is a variable multi-signal generator for selectively adjusting said center frequency to cause said plurality of signals to cover a differing of the selected frequency band; a modulator connected to said multi-signal generator for selectively and simultaneously modulating said plurality of signals; a control unit for selectively controlling said multi-signal generator center frequency; a decoder adapted to prevent a transmission of said plurality of signals in response to receipt of an emergency transmission. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A dual-mode transmitter, comprising:
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a first signal generator for simultaneously providing a plurality of carrier signals within a frequency band and having a relative frequency spacing, and including an amplitude modulator of said plurality of said plurality of signals according to a modulation signal; a second signal generator for selectively providing a selectable frequency signal, and including a frequency modulator of said selectable frequency according to a modulation signal; a mixer receiving the output signals of said first and second signal generators, and providing an output signal; a power amplifier for selectively receiving said signals corresponding to said plurality of signals from said first signal generator and said mixer output signal, providing a signal to an antenna according to said selectively received signal; a control means for selectably enabling said first signal amplitude modulator in a first mode, and said second signal generator frequency modulator in a second mode; and a decoder for detecting an emergency transmission and adapted to disable the dual-mode transmitter so that said signal is not provided to said antenna. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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Specification