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US 5,394,117 AGranted
Direct digital synthesizer-based injection locked oscillator
AssigneeAIL Systems, Inc.
InventorLeonard D. Cohen
Life of this patent
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AssigneeAIL Systems, Inc.
InventorLeonard D. Cohen
Estimating the term…
A direct digitally synthesizer-based, injection locked oscillator includes a direct digital synthesizer for generating a digitally synthesized signal at frequency f.sub.0, an analog oscillator circuit for generating an analog signal at frequency f.sub.1 and a filter coupled to the direct digital synthesizer for filtering the digitally synthesized signal to provide a signal at frequency Nf.sub.0. N may be an integer from 1 to 10. Also included is a coupler to couple the filtered, digitally synthesized signal into the analog oscillator to lock the frequency of the analog output signal to the frequency of the digitally synthesized signal such that the frequency f.sub.1 is equal to the frequency Nf.sub.0. The coupler also electrically couples the analog signal from the analog oscillator circuit to a second filter to filter the analog signal. An amplifier electrically coupled to the second filter amplifies the filtered signal to provide an analog oscillator output signal. The direct digital synthesizer may be used to high-order, sub-harmonically injection lock the analog oscillator circuit thereby providing an output signal reflecting a frequency up-conversion in order to broaden the frequency range of the synthesized analog output signal beyond that of the direct digital synthesizer.
A method of tuning an analog oscillator to cause the analog oscillator to generate an oscillator output signal substantially free from spectral impurities, the analog oscillator including a direct digital synthesizer and an analog oscillator circuit, the method comprising the steps of:
A method of tuning an analog oscillator to cause the analog oscillator to generate a frequency up-converted oscillator output signal substantially free from spectral impurities, the analog oscillator including a direct digital synthesizer and an analog oscillator circuit, the method comprising the steps of:
A direct digital synthesizer-based, injection locked oscillator for generating an oscillator output signal that is substantially free from spectral impurities, comprising:
A direct digital synthesizer-based, injection locked oscillator for generating an oscillator output signal that is substantially free from spectral impurities, comprising:
Dependencies are inferred from the claim text.