Noise rejection antenna system for nonmetallic marine vessels
First Claim
1. A noise attenuating antenna system connectable to the antenna input of an AM-FM recreational receiver having a single antenna input comprising:
- a first antenna sensitive to RF signals in the AM radio frequency band;
a second antenna sensitive to the RF signals in the FM frequency band;
amplifier means for amplifying the RF signals received by said first antenna;
signal attenuation means for attenuating the RF signals received by said second antenna;
impedance matching and signal routing means for routing the RF signals received from said amplifier means and said signal attenuation means to said single antenna input of said AM-FM receiver and for matching the impedance of said received RF signals to the input impedance of said AM-FM receiver; and
switch means switchable between an AM position and an FM position, said switch means in said AM position actuating said amplifier means to pass the RF signals received from said first antenna to said impedance matching and signal routing means and actuating said signal attenuation means to pass to ground the RF signals received by said second antenna, said switch means in said FM position deactuating said amplifier means blocking the signals received by said first antenna and deactuating said signal attenuation means permitting the RF signals received by said second antenna to be passed to said impedance matching and signal routing means.
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Accused Products
Abstract
A noise attenuating antenna system for AM-FM recreational receivers having a single RF input for use on nonmetallic marine vessels or any other vehicle where electric noise presents a problem. The antenna system has at least a shielded loop antenna for receiving radio signals in the AM frequency band and a dipole antenna for receiving radio signals in the FM frequency band. An impedance matching and signal routing circuit passes the signals received by the shielded loop antenna and the dipole antenna to the recreational receiver. An amplifier, whose operation is controlled by a remotely located selection switch, passes the RF signals received by the loop antenna to the impedance matching and signal routing circuit and a signal attenuating circuit passes to ground the RF signals recevied by the dipole antenna when the selection switch is in an AM position. The amplifier is de-energized blocking the signals from the shielded loop antenna and the signal attenuating circuit generates a high impedance to ground for the RF signals received by the dipole antenna when the selector switch is in the FM position. The antenna system may also have a dipole antenna tuned for the frequency of a weather station to accommodate recreational receivers having a weather band channel.
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Citations
22 Claims
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1. A noise attenuating antenna system connectable to the antenna input of an AM-FM recreational receiver having a single antenna input comprising:
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a first antenna sensitive to RF signals in the AM radio frequency band; a second antenna sensitive to the RF signals in the FM frequency band; amplifier means for amplifying the RF signals received by said first antenna; signal attenuation means for attenuating the RF signals received by said second antenna; impedance matching and signal routing means for routing the RF signals received from said amplifier means and said signal attenuation means to said single antenna input of said AM-FM receiver and for matching the impedance of said received RF signals to the input impedance of said AM-FM receiver; and switch means switchable between an AM position and an FM position, said switch means in said AM position actuating said amplifier means to pass the RF signals received from said first antenna to said impedance matching and signal routing means and actuating said signal attenuation means to pass to ground the RF signals received by said second antenna, said switch means in said FM position deactuating said amplifier means blocking the signals received by said first antenna and deactuating said signal attenuation means permitting the RF signals received by said second antenna to be passed to said impedance matching and signal routing means. - 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 noise attenuating antenna system connectable to the input of an AM-FM recreational receiver having a single antenna input comprising:
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a first antenna responsive to radio frequency signals in the AM transmission band; a second antenna responsive to radio frequency signals in the FM transmission band; an AM-FM switch having a first position corresponding to AM ratio station frequencies and a second position corresponding FM radio station frequencies; an impedance matching and signal routing circuit for routing received radio frequency signals to the single antenna input of the recreational receiver; a first electronic switch for passing the radio frequency signals received by said first antenna to said impedance matching and signal routing circuit in response to said AM-FM switch being in said first position and blocking said radio frequency signals received by said first antenna in response to said AM-FM switch being in said second position; and a second electronic switch for passing to ground said radio frequency signals received by said second antenna when said AM-FM switch is in said first position and for passing to said impedance matching and signal routing circuit the radio frequency signals received by said second antenna when said AM-FM switch is in said second position. - View Dependent Claims (20, 21, 22)
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Specification