US4331941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital phase domain amplitude modulation method and apparatus
Assignee: HP Inc
•
Filing: 1980-02-29
•
Granted: 1982-05-25
•
Expires: 2000-02-29
Abstract
Abstract A modulating signal is applied to an analog-to-digital converter which addresses a read-only memory phase look-up table. The read-only memory phase look-up table output is applied to a polarity generator. The polarity generator output and output from a phase accumulator are input to a phase adder. The phase adder output is applied to the input of a sine look-up read-only memory whose output is applied to a digital-to-analog converter and low-pass filtered to produce an amplitude-modulated carrier signal. The invention thereby digitally amplitude modulates a carrier signal in the phase domain without any multiplication being required.
Inventors
- 👤 Al Kovalick
- 👤 Rolly Hassun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:05
CPC Classifications
H; H03; H03C; H03C1/00; H03C1/50; H03B; H03B2201/00; H03B2201/02; H03B2201/0275; H03B2201/0283; H03B28/00
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
232 words
Digital apparatus comprising: phase accumulation means for accumulating a linearly increasing phase count and producing a digital phase signal corresponding to the phase count in response to receiving a differential phase input; adding means having a first input coupled to receive the digital phase signal, a second input and an output for adding signals applied to the first and second inputs and producing a summation signal corresponding to the addition at the output; sine look-up means coupled to receive the adding means output for producing a digital sine value signal in response to the summation signal; digital-to-analog conversion means coupled to receive the digital sine value signal for producing an analog signal output in response to the digital sine value signal; filtering means coupled to receive the analog signal output for producing a selected spectrum of the analog signal as an output; analog-to-digital conversion means coupled to receive an applied input signal for producing a digital modulation signal in response to the applied input signal; phase conversion means coupled to receive the digital modulation signal for producing a digital modulation phase signal in response to the digital modulation signal; and polarity generation means coupled to the adding means second input and to the phase conversion means to receive the digital modulation signal for producing an alternately polarized digital modulation signal and applying the alternately polarized digital modulation signal to the adding means.
Claim 2
Dependent Claim
232 words
Digital apparatus comprising: phase accumulation means for accumulating a linearly increasing phase count and producing a digital phase signal corresponding to the phase count in response to receiving a differential phase input; adding means having a first input coupled to receive the digital phase signal, a second input and an output for adding signals applied to the first and second inputs and producing a summation signal corresponding to the addition at the output; sine look-up means coupled to receive the adding means output for producing a digital sine value signal in response to the summation signal; digital-to-analog conversion means coupled to receive the digital sine value signal for producing an analog signal output in response to the digital sine value signal; filtering means coupled to receive the analog signal output for producing a selected spectrum of the analog signal as an output; analog-to-digital conversion means coupled to receive an applied input signal for producing a digital modulation signal in response to the applied input signal; phase conversion means coupled to receive the digital modulation signal for producing a digital modulation phase signal in response to the digital modulation signal; and polarity generation means coupled to the adding means second input and to the phase conversion means to receive the digital modulation signal for producing an alternately polarized digital modulation signal and applying the alternately polarized digital modulation signal to the adding means.
Claim 3
Dependent Claim
52 words
Apparatus as in claim 1 wherein phase accumulation means comprise: an adder having a first input coupled to receive the differential phase input, a second input and an output; and a latch coupled to receive the adder output and an applied clock signal and an output coupled to the adder second input.
Claim 4
Dependent Claim
13 words
Apparatus as in claim 1 wherein sine look-up means comprises a read-only memory.
Claim 5
Dependent Claim
13 words
Apparatus as in claim 1 wherein sine look-up means comprises a random-access memory.
Claim 6
Dependent Claim
12 words
Apparatus as in claim 1 wherein filtering means comprises a low-pass filter.
Claim 7
Dependent Claim
13 words
Apparatus as in claim 1 wherein phase conversion means comprises a read-only memory.
Claim 8
Dependent Claim
13 words
Apparatus as in claim 1 wherein phase conversion means comprises a random-access memory.
Claim 9
Dependent Claim
88 words
Apparatus as in claim 1 wherein polarity generation means comprise: a plurality of exclusive OR gates, each having a first input, a second input and an output; dividing means coupled to receive an applied clock signal for producing a divided clock signal as an intput; means for coupling the first input of each of the plurality of exclusive OR gates to receive the divided clock signal; and means for coupling the second input of each of the plurality of exclusive OR gates to receive the digital modulation signal.
Claim 10
Dependent Claim
205 words
Digital apparatus comprising: phase accumulation means for accumulating a linearly increasing phase count and producing a digital phase signal corresponding to the phase count in response to receiving a differential phase input; adding means having a first input coupled to receive the digital phase signal, a second input and an output for adding signals applied to the first and second inputs and producing a summation signal corresponding to the addition at the output; sine look-up means coupled to receive the adding means output for producing a digital sine value signal in response to the summation signal; digital-to-analog conversion means coupled to receive the digital sine value signal for producing an analog signal output in response to the digital sine value signal; filtering means coupled to receive the analog signal output for producing a selected spectrum of the analog signal as an output; phase conversion means coupled to receive an applied digital modulation signal for producing a digital modulation phase signal in response to the digital modulation signal; and polarity generation means coupled to the adding means second input and to receive the digital modulation signal for producing an alternately polarized digital modulation signal and applying the alternately polarized digital modulation signal to the adding means.
Claim 11
Dependent Claim
205 words
Digital apparatus comprising: phase accumulation means for accumulating a linearly increasing phase count and producing a digital phase signal corresponding to the phase count in response to receiving a differential phase input; adding means having a first input coupled to receive the digital phase signal, a second input and an output for adding signals applied to the first and second inputs and producing a summation signal corresponding to the addition at the output; sine look-up means coupled to receive the adding means output for producing a digital sine value signal in response to the summation signal; digital-to-analog conversion means coupled to receive the digital sine value signal for producing an analog signal output in response to the digital sine value signal; filtering means coupled to receive the analog signal output for producing a selected spectrum of the analog signal as an output; phase conversion means coupled to receive an applied digital modulation signal for producing a digital modulation phase signal in response to the digital modulation signal; and polarity generation means coupled to the adding means second input and to receive the digital modulation signal for producing an alternately polarized digital modulation signal and applying the alternately polarized digital modulation signal to the adding means.
Claim 12
Dependent Claim
29 words
Apparatus as in claim 9 comprising analog-to-digital conversion means coupled to receive an applied input signal for producing the digital modulation signal in response to the applied input signal.
Claim 13
Dependent Claim
52 words
Apparatus as in claim 9 wherein phase accumulation means comprise: an adder having a first input coupled to receive the differential phase input, a second input and an output; and a latch coupled to receive the adder output and an applied clock signal and an output coupled to the adder second input.
Claim 14
Dependent Claim
13 words
Apparatus as in claim 9 wherein sine look-up means comprises a read-only memory.
Claim 15
Dependent Claim
13 words
Apparatus as in claim 9 wherein sine look-up means comprises a random-access memory.
Claim 16
Dependent Claim
12 words
Apparatus as in claim 9 wherein filtering means comprises a low-pass filter.
Claim 17
Dependent Claim
13 words
Apparatus as in claim 9 wherein phase conversion means comprises a read-only memory.
Claim 18
Dependent Claim
13 words
Apparatus as in claim 9 wherein phase conversion means comprises a random-access memory.
Claim 19
Dependent Claim
88 words
Apparatus as in claim 9 wherein polarity generation means comprise: a plurality of exclusive OR gates, each having a first input, a second input and an output; dividing means coupled to receive an applied clock signal for producing a divided clock signal as an output; means for coupling the first input of each of the plurality of exclusive OR gates to receive the divided clock signal; and means for coupling the second input of each of the plurality of exclusive OR gates to receive the digital modulation signal.
Claim 20
Dependent Claim
179 words
Digital precision carrier attenuation apparatus comprising: phase accumulation means for accumulating a linearly increasing phase count and producing a digital phase signal corresponding to the phase count in response to receiving a differential phase input; adding means having a first input coupled to receive the digital phase signal, a second input and an output for adding signals applied to the first and second inputs and producing a summation signal corresponding to the addition at the output; sine look-up means coupled to receive the adding means output for producing a digital sine value signal in response to the summation signal; digital-to-analog conversion means coupled to receive the digital sine value signal for producing an analog signal output in response to the digital sine value signal; filtering means coupled to receive the analog signal output for producing a selected spectrum of the analog signal as an output; and polarity generation means coupled to the adding means second input and a digital input signal for producing an alternately polarized digital signal and applying the alternately polarized digital signal to the adding means.
Claim 21
Dependent Claim
179 words
Digital precision carrier attenuation apparatus comprising: phase accumulation means for accumulating a linearly increasing phase count and producing a digital phase signal corresponding to the phase count in response to receiving a differential phase input; adding means having a first input coupled to receive the digital phase signal, a second input and an output for adding signals applied to the first and second inputs and producing a summation signal corresponding to the addition at the output; sine look-up means coupled to receive the adding means output for producing a digital sine value signal in response to the summation signal; digital-to-analog conversion means coupled to receive the digital sine value signal for producing an analog signal output in response to the digital sine value signal; filtering means coupled to receive the analog signal output for producing a selected spectrum of the analog signal as an output; and polarity generation means coupled to the adding means second input and a digital input signal for producing an alternately polarized digital signal and applying the alternately polarized digital signal to the adding means.
Claim 22
Dependent Claim
29 words
Apparatus as in claim 18 comprising an analog-to-digital conversion means coupled to receive an applied input signal for producing the digital signal in response to the applied input signal.
Claim 23
Dependent Claim
52 words
Apparatus as in claim 18 wherein phase accumulation means comprise: an adder having a first input coupled to receive the differential phase input, a second input and an output; and a latch coupled to receive the adder output and an applied clock signal and an output coupled to the adder second input.
Claim 24
Dependent Claim
13 words
Apparatus as in claim 18 wherein sine look-up means comprises a read-only memory.
Claim 25
Dependent Claim
13 words
Apparatus as in claim 18 wherein sine look-up means comprises a random-access memory.
Claim 26
Dependent Claim
12 words
Apparatus as in claim 18 wherein filtering means comprises a low-pass filter.
Claim 27
Independent Claim
73 words
A method for digitally amplitude-modulating an applied carrier signal in the phase domain comprising the steps of: phase-converting a modulating signal; alternating the polarity of the phase-converted modulating signal; accumulating a linearly-increasing phase count; adding the polarity alternating phase-converted modulating signal and the accumulated phase count; converting the sum of the addition to phase values of a sine wave; digitally converting the phase values to an analog signal; and filtering the analog signal.
Claim 28
Independent Claim
73 words
A method for digitally amplitude-modulating an applied carrier signal in the phase domain comprising the steps of: phase-converting a modulating signal; alternating the polarity of the phase-converted modulating signal; accumulating a linearly-increasing phase count; adding the polarity alternating phase-converted modulating signal and the accumulated phase count; converting the sum of the addition to phase values of a sine wave; digitally converting the phase values to an analog signal; and filtering the analog signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-24 | 1985-11-23 | 1986-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-24 | 1989-11-23 | 1990-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-24 | 1993-11-23 | 1994-05-25 | $7700.00 | Window Closed / Lapsed |