Multiple band scanning radio
First Claim
1. Radio apparatus comprising:
- radio frequency means for receiving radio frequency energy through any of a plurality of different radio frequency paths;
mixer means for converting said radio frequency energy to intermediate frequency energy;
processing means for converting said intermediate frequency energy to audio sound vibrations;
control means for selecting the frequency of radio frequency energy that is to be converted to intermediate frequency energy;
said control means including local oscillator means for generating a plurality of different frequency local oscillations for application to said mixer means and control signals indicating the one of said different frequency local oscillations to be transmitted to said mixer means;
said mixer means including means for selecting one of said radio frequency paths in said radio frequency means in response to said control signals from said local oscillator means;
said mixer means including mixer input conductor means for carrying local oscillations to said mixer and a plurality of different possible conductive paths from said local oscillator means to said mixer input conductor means for said local oscillations;
some of said conductive paths having a different impedance than other of said conductive paths; and
means for selecting the path said local oscillations take to said mixer input conductor means in response to said signals.
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Accused Products
Abstract
To scan channels in a plurality of bands using a single first mixer, an FET transistor in an adaptive first mixer of the scanning radio, in response to a signal from a counter in the scanning local oscillator representing the frequency band of the channel being scanned, has: (1) its gate electrode connected to the output of a selected RF amplifier of a plurality of RF amplifiers for different bands; and (2) its source electrode electrically connected to receive local oscillations through a selected one of a plurality of different impedance networks. These connections enable the adaptive first mixer to maintain sufficiently high conversion gain when receiving signals on channels in any one of a plurality of different frequency bands.
140 Citations
9 Claims
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1. Radio apparatus comprising:
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radio frequency means for receiving radio frequency energy through any of a plurality of different radio frequency paths; mixer means for converting said radio frequency energy to intermediate frequency energy; processing means for converting said intermediate frequency energy to audio sound vibrations; control means for selecting the frequency of radio frequency energy that is to be converted to intermediate frequency energy; said control means including local oscillator means for generating a plurality of different frequency local oscillations for application to said mixer means and control signals indicating the one of said different frequency local oscillations to be transmitted to said mixer means; said mixer means including means for selecting one of said radio frequency paths in said radio frequency means in response to said control signals from said local oscillator means; said mixer means including mixer input conductor means for carrying local oscillations to said mixer and a plurality of different possible conductive paths from said local oscillator means to said mixer input conductor means for said local oscillations; some of said conductive paths having a different impedance than other of said conductive paths; and means for selecting the path said local oscillations take to said mixer input conductor means in response to said signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification