Four quadrant multiplying apparatus and method
AssigneeAnalog Devices, Inc.
InventorEric Nestler
Life of this patent
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Abstract
An apparatus and a method for multiplying two time varying signals to produce a four quadrant, multiplied signal is provided. In one embodiment of the present invention, an apparatus for multiplying a first signal with a second signal includes an analog-to-digital converter that provides a first digital signal representative of the first signal, a first modulator that provides a first modulated signal representative of the second signal, a multiplier that multiplies the first digital signal by the first modulated signal and provides a second digital signal representative of a result of a multiplication of the first signal and the second signal, and a first filter having an input to receive the second digital signal and having an output that provides the multiplied signal.
Claims15
An apparatus for multiplying a first signal by a second signal to provide a multiplied signal, the apparatus comprising:
- an analog-to-digital converter having an input to receive the first signal, and an output that provides a first digital signal representative of the first signal;
- a first modulator having an input that receives the second signal and an output that provides a first modulated signal representative of the second signal;
- a multiplier having a first input coupled to the output of the analog-to-digital converter to receive the first digital signal, a second input coupled to the output of the first modulator that receives the first modulated signal, and an output that provides the multiplied signal;
- and
- a first filter having an input that receives the multiplied signal and an output that provides a filtered multiplied signal;
- wherein the analog-to-digital converter includes:
- a second modulator having an input, coupled to the input of the analog to digital converter to receive the first signal, and having an output that provides a second modulated signal;
- a second filter having an input coupled to the output of the second modulator to receive the second modulated signal and having an output that provides a filtered signal;
- and
- an interpolator having an input coupled to the output of the filter to receive the filtered signal and an output that provides the first digital signal.
A method for multiplying a first signal with a second signal to provide a multiplied signal, the method comprising steps of:
- generating an n-bit signal corresponding to the first signal, the n-bit signal having n bits, each of the n bits having one of a first or a second value respectively corresponding to a first and a second logical value;
- generating a modulated signal corresponding to the second signal, the modulated signal having one of a first or a second value respectively corresponding to a first and a second logical value;
- generating the multiplied signal such that the multiplied signal is equal to the n-bit signal when the modulated signal has the first logical value, and such that the multiplied signal is equal to an inversion of the n-bit signal when the modulated signal is equal to the second logical value, wherein the inversion of the n-bit signal corresponds to the first n-bit signal with each of the bits inverted from the first logical value to the second logical value or from the second logical value to the first logical value;
- and
- filtering the multiplied signal;
- wherein the step of generating the n-bit signal includes steps of:
- generating a one-bit modulated signal corresponding to the first signal;
- filtering the one-bit modulated signal to provide a filtered signal;
- and
- sampling the filtered signal to generate the n-bit signal.
An apparatus for multiplying a first signal with a second signal to provide a multiplied signal, the apparatus comprising:
- means for generating an n-bit signal corresponding to the first signal, the n-bit signal having n bits, each of the n bits having one of a first or a second value respectively corresponding to a first and a second logical value;
- means for generating a modulated signal corresponding to the second signal, the modulated signal having one of a first or a second value respectively corresponding to a first and a second logical value;
- means for generating the multiplied signal, coupled to the means for generating the first input signal and coupled to the means for generating the first one-bit signal, the multiplied signal being equal to the n-bit signal when the modulated signal has the first logical value, and the multiplied signal being equal to an inversion of the n-bit signal when the modulated signal is equal to the second logical value, wherein the inversion of the n-bit signal corresponds to the n-bit signal with each of the bits inverted from the first logical value to the second logical value or from the second logical value to the first logical value;
- and
- means for filtering the multiplied signal to generate a filtered multiplied signal, the means for filtering being coupled to the means for generating the multiplied signal to receive the multiplied signal;
- wherein the means for generating the n-bit signal includes:
- means for generating a one-bit modulated signal corresponding to the first signal;
- means for filtering the one-bit modulated signal to provide a filtered signal;
- and
- means for sampling the filtered signal to generate the n-bit signal.
Dependencies are inferred from the claim text.