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US 4,048,571 AGranted
Frequency doubler
AssigneeXerox Corporation
InventorCharles L. Jacobson
Life of this patent
Estimating the term…
Abstract
Circuitry for doubling the frequency of a periodic input signal. The input periodic wave is applied to a differencing amplifier whose inputs are biased in such a manner that the output signal changes level twice during each half-cycle of the input periodic wave. This changing of level occurs at the same relative points in both half-cycles of the periodic input wave.
Claims6
Circuitry for doubling the frequency of a periodic input signal comprising
- a differencing amplifier having a first input terminal, a second input terminal, and an output terminal, said amplifier providing a first signal at said output terminal when said first terminal has a greater applied signal level than said second terminal and providing a second signal at said output terminal when said second terminal has a greater applied signal level than said first terminal,
- biasing means connected to said amplifier input terminals for providing a higher signal level to said second terminal than to said first terminal, said biasing means including
- a single voltage source,
- a first resistor connected between said voltage source and said amplifier first input terminal, and
- a second resistor connected between said voltage source and said amplifier second input terminal, said second resistor having a smaller resistance value than said first resistor, and
- input means connected to said input terminals for increasing the signal level at said first terminal when said input signal is above a predetermined level and for decreasing the signal level at said second terminal when said input signal is below said predetermined level, said input means including
- means for receiving said input signal,
- a first branch adapted to unidirectionally conduct current from said receiving means to said amplifier first input terminal when said input signal is above said predetermined level, and
- a second branch adapted to unidirectionally conduct current from said amplifier second input terminal to said receiving means when said input signal is below said predetermined level.
6 more elements
Circuitry for doubling the frequency of a periodic input signal comprising
- a current differencing amplifier having a first input terminal, a second input terminal, and an output terminal, said amplifier providing a first signal at said output terminal when the current into said amplifier is greater at said first terminal than at said second terminal and providing a second signal at said output terminal when the current into said amplifier is greater at said second terminal than at said first terminal,
- current providing means connected to said amplifier input terminals for providing more current to said amplifier at said second terminal than at said first terminal, said current providing means including
- a single voltage source,
- a first resistor connected between said voltage source and said amplifier first input terminal, and
- a second resistor connected between said voltage source and said amplifier second input terminal, said second resistor having a smaller resistance value than said first resistor, and
- input means connected to said input terminals for providing current to said amplifier at said first terminal when said input signal is above a predetermined level and for drawing current from said amplifier at said second terminal when said input signal is below said predetermined level, said input means including
- means for receiving said input signal,
- a first branch adapted to unidirectionally conduct current from said receiving means to said amplifier first input terminal when said input signal is above said predetermined level, and
- a second branch adapted to unidirectionally conduct current from said amplifier second input terminal to said receiving means when said input signal is below said predetermined level.
6 more elements
Dependencies are inferred from the claim text.