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US 4,789,837 AGranted
Switched capacitor mixer/multiplier
AssigneeSangamo Weston, Inc.
InventorTimothy J. Ridgers
Life of this patent
Estimating the term…
Abstract
A sequence of samples of a time varying signal is multiplied by respective, corresponding, multiplicands corresponding to values of a separate signal. The multiplicands are provided as ratios of capacitances switched into and out of a circuit between the input time varying voltage and an accumulating integrator. The arrangement is used to provide multiplication of a time varying signal by corresponding amplitudes of a sinusoid without requiring generation of a sinusoid. The arrangement is used for sampling, detecting signals utilizing a simulated local oscillator signal, and for generation of an arbitrary time varying function.
Claims20
Signal sampling apparatus comprising:
- input means for providing an input signal to be sampled;
- multiplying means for multiplying sequential values of the input signal by predetermined respective multiplicands at predetermined sample times;
- and
- summing means for summing the multiplied values of the signal;
- and for providing an output signal corresponding to a sum of respective products of the input signal values and the respective multiplicands wherein
- said multiplying means comprises a plurality of switched capacitor means, including plural capacitors having predetermined capacitance values and controlled switch means connected to said plural capacitors for providing controllably variable interconnections of capacitors between said input means and said summing means,
- said controlled switch means comprising, for each of said capacitors, an input and an output switch respectively connected to an input terminal and an output terminal of each said capacitor and connected to be controlled by different control signals for providing two-phase operation thereof,
- wherein in a first phase an input switch of a predetermined capacitor connects said capacitor to said input means for receiving said input signal and an output switch of said predetermined capacitor connects said predetermined capacitor to complete a loop with said input means,
- and in a second phase said output switch of said predetermined capacitor connects said predetermined capacitor to said summing means and said input switch of said predetermined capacitor connects said predetermined capacitor to complete a loop with said summing means,
- thereby providing controllable ratios of said plural capacitors as multipliers for said input signal provided at said predetermined sample times to said summing means.
7 more elements
Signal mixing apparatus comprising:
- input means for inputting a received signal to be mixed with a local signal having a predetermined frequency;
- multiplying means for multiplying at predetermined times sequential values of the received signal by predetermined respective multiplicands corresponding to a sequence of values of the local signal;
- and
- summing means for summing the multiplied values of the signal and for providing an output signal corresponding to a sum of respective products of the values of the received signal and the respective values of the local signal, wherein
- said multiplying means comprises a plurality of switched capacitor means, including plural capacitors having predetermined capacitance values and controlled switch means connected to said plural capacitors for providing controllably variable interconnections of capacitors between said input means and said summing means,
- said controlled switch means comprising, for each of said capacitors, an input and an output switch respectively connected to an input terminal and an output terminal of each said capacitor and connected to be controlled by different control signals for providing two-phase operation thereof,
- wherein in a first phase an input switch of a predetermined capacitor connects said capacitor to said input means for receiving said received signal and an output switch of said predetermined capacitor connects said predetermined capacitor to complete a loop with said input means,
- and in a second phase said output switch of said predetermined capacitor connects said predetermined capacitor to said summing means and said input switch of said predetermined capacitor connects said predetermined capacitor to complete a loop with said summing means,
- thereby providing controllable ratios of said plural capacitors as multipliers for said sequential values of the received signal provided at said predetermined times to said summing means.
6 more elements
Function generator apparatus comprising:
- input means for providing an input DC signal;
- multiplying means for multiplying sequential samples of the input DC signal by predetermined multiplicands at predetermined times;
- and
- summing means for summing the multiplied values of the DC signal and for providing an output signal corresponding to a sequence of products of said DC signal and said predetermined multiplicands;
- wherein
- said multiplying means comprises a plurality of switched capacitor means, including plural capacitors having predetermined capacitance values and controlled switch means connected to said plural capacitors for providing controllably variable interconnections of capacitors between said input means and said summing means,
- said controlled switch means comprising, for each of said capacitors, an input and an output switch respectively connected to an input terminal and an output terminal of each said capacitor and connected to be controlled by different control signals for providing two-phase operation thereof,
- wherein in a first phase an input switch of a predetermined capacitor connects said capacitor to said input means for receiving said input DC signal and an output switch of said predetermined capacitor connects said predetermined capacitor to complete a loop with said input means,
- and in a second phase said output switch of said predetermined capacitor connects said predetermined capacitor to said summing means and said input switch of said predetermined capacitor connects said predetermined capacitor to complete a loop with said summing means,
- thereby providing controllable ratios of said plural capacitors as multipliers for said input DC signal provided at said predetermined times to said summing means.
7 more elements
Signal multiplying apparatus comprising:
- input means for inputting a first signal to be multiplied by a plurality of multiplicands corresponding to amplitude values of a second signal;
- multiplying means for multiplying at predetermined times a sequence of values of the first signal by a sequence of respective multiplicands corresponding to said values of said second signal;
- and
- summing means for summing the multiplied values of the first signal and for providing an output corresponding to a sum of respective products of corresponding values of said first and second signals;
- wherein
- said multiplying means comprises a plurality of switched capacitor means, including plural capacitors having predetermined capacitance values and controlled switch means connected to said plural capacitors for providing controllably variable interconnections of capacitors between said input means and said summing means,
- said controlled switch means comprising, for each of said capacitors, an input and an output switch respectively connected to an input terminal and an output terminal of each said capacitor and connected to be controlled by different control signals for providing two-phase operation thereof,
- wherein in a first phase an input switch of a predetermined capacitor connects said capacitor to said input means for receiving said first signal and an output switch of said predetermined capacitor connects said predetermined capacitor to complete a loop with said input means,
- and in a second phase said output switch of said predetermined capacitor connects said predetermined capacitor to said summing means and said input switch of said predetermined capacitor connects said predetermined capacitor to complete a loop with said summing means,
- thereby providing to said summing means at said predetermined times controllable ratios of said plural capacitors as said sequence of respective multiplicands for said sequence of values of said first signal provided.
7 more elements
Dependencies are inferred from the claim text.