Wide band radio-frequency converter having multiple use of intermediate frequency translators
First Claim
1. A frequency converter comprising:
- a first frequency-converting stage to which a received radio frequency signal is applied, said first frequency-converting stage including;
a first frequency translator having an input for the received radio frequency signal an input for a local oscillator signal and an output;
a source of a tunable radio-frequency signal coupled to the input for the local oscillator signal;
means for coupling the output of the first frequency translator to any one of a first plurality of bandpass filters;
a second frequency-converting stage including a second frequency translator having;
an input including a switch for selecting any of a plurality of the outputs of said first plurality of bandpass filters, an input for a local oscillator signal and an output;
a by-pass path coupled to the switch to bypass the second frequency translator;
a second source of a local oscillator signal coupled to the input for the local oscillator signal of the second frequency translator;
means for selectively coupling the output of the second frequency translator or the output of the bypass path to a third frequency translator or to one of a plurality of further paths in the frequency converter; and
a third frequency-converting stage including;
the third frequency translator having an input coupled to the means for selectively coupling, and input for a third local oscillator signal and an output;
a plurality of third stage bypass paths coupling to the means for selectively coupling for bypassing the third frequency translator; and
means for selectively transmitting the output of the third frequency translator or the output of any one of the plurality of the third stage bypass paths.
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Accused Products
Abstract
A wideband RF-to-IF frequency converter providing multiple use of frequency conversion components for many different types of RF input signals. In specific examples, many different types of signals for communication, navigation, and for interrogation are processed through at least partly common frequency-conversion channels. Such RF input signals in the range from approximately 2 MHz to 2,000 MHz are converted to output IF frequencies, such as 1 MHz and 30 MHz, for further processing in the common receiver. Some narrow band signals, after conversion to IF, are subjected to off-center filtering in relatively broadband IF filters. Input RF filters are not used. Among several frequency conversion stages, only one of the local oscillator signals is tunable; but it is made tunable in relatively small, precise steps by using a double phase-locked loop arrangement in the frequency synthesizer.
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Citations
11 Claims
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1. A frequency converter comprising:
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a first frequency-converting stage to which a received radio frequency signal is applied, said first frequency-converting stage including; a first frequency translator having an input for the received radio frequency signal an input for a local oscillator signal and an output; a source of a tunable radio-frequency signal coupled to the input for the local oscillator signal; means for coupling the output of the first frequency translator to any one of a first plurality of bandpass filters; a second frequency-converting stage including a second frequency translator having; an input including a switch for selecting any of a plurality of the outputs of said first plurality of bandpass filters, an input for a local oscillator signal and an output; a by-pass path coupled to the switch to bypass the second frequency translator; a second source of a local oscillator signal coupled to the input for the local oscillator signal of the second frequency translator; means for selectively coupling the output of the second frequency translator or the output of the bypass path to a third frequency translator or to one of a plurality of further paths in the frequency converter; and a third frequency-converting stage including; the third frequency translator having an input coupled to the means for selectively coupling, and input for a third local oscillator signal and an output; a plurality of third stage bypass paths coupling to the means for selectively coupling for bypassing the third frequency translator; and means for selectively transmitting the output of the third frequency translator or the output of any one of the plurality of the third stage bypass paths. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification