EP0405445A2
Expired / Lapsed
EP
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Output waveform control circuit
Assignee: NEC Corp
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Filing: 1990-06-26
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Granted: —
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Expires: 2010-06-26
Abstract
Abstract An output waveform control circuit for a time division multiple access system (TDMA), including a second driving circuit (6) which sends a control signal to the power amplifier (4) in accordance with a signal outputted by the comparator circuit (8). Thus, by controlling the operating voltage of the power amplifier simultaneously with the control of the level input signal from the input level control circuit (3), the output characteristic of the power amplifier (4), including a class C or the like amplifier having a non-linear input/output characteristic, is prevented from varying abruptly, and the output waveform of the power amplifier (4) is so controlled as to have gently sloped leading and trailing edges.
Inventors
- 👤 Tsuguo C/O Nec Corporation Hori
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 17:05
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3036; H03G3/3042; H03G3/3047
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
126 words
An output waveform control circuit comprising: input level control means for controlling the level of an input signal; power amplifier means for ampilfying the output signal of said input level control means in accordance with an operating voltage; detector circuitmeans for detecting the envelope of the output signal of said power amplifier means; control signal generator means for generating a reference signal having gently sloped leading and trailing edges; comparator circuit means for comparing the output signal of said detector circuit means with said reference signal to provide an error signal; first driving means for providing said input level control means with a level control signal derived from said error signal; and second driver means for controlling said operating voltage in response to said error signal.
Claim 2
Dependent Claim
126 words
An output waveform control circuit comprising: input level control means for controlling the level of an input signal; power amplifier means for ampilfying the output signal of said input level control means in accordance with an operating voltage; detector circuitmeans for detecting the envelope of the output signal of said power amplifier means; control signal generator means for generating a reference signal having gently sloped leading and trailing edges; comparator circuit means for comparing the output signal of said detector circuit means with said reference signal to provide an error signal; first driving means for providing said input level control means with a level control signal derived from said error signal; and second driver means for controlling said operating voltage in response to said error signal.
Claim 3
Dependent Claim
45 words
An output waveform control circuit as claimed in claim 1, wherein said input level control means comprises a series of cascading diodes for receiving said level control signal simultaneously with said input signal to provide an output signal having gently sloped leading and trailing edges.
Claim 4
Dependent Claim
28 words
An output waveform control circuit as claimed in claim 1 or 2, wherein said second driver means comprises a Darlington circuit including an NPN and a PNP transistor.
Claim 5
Dependent Claim
46 words
An output waveform control circuit as claimed in claims 1, 2 or 3, wherein said power amplifier means comprises a series of cascading amplifiers supplied with said input signal simultaneously with said operating voltage to provide an output waveform having gently sloped leading and trailing edges.
Claim 6
Dependent Claim
92 words
An output waveform control circuit comprising: power amplifier means for amplifying an input signal in accordance with an operating voltage; detector circuit means for detecting the envelope of an output signal from said power amplifier means; control signal generator means for generating a reference signal having gently sloped leading and trailing edges; comparator circuit means for comparing the output signal of said detector circuit means with said reference signal from said comparator circuit means, to provide an error signal; driver means for controlling said operating voltage in response to said error signal.
Claim 7
Dependent Claim
92 words
An output waveform control circuit comprising: power amplifier means for amplifying an input signal in accordance with an operating voltage; detector circuit means for detecting the envelope of an output signal from said power amplifier means; control signal generator means for generating a reference signal having gently sloped leading and trailing edges; comparator circuit means for comparing the output signal of said detector circuit means with said reference signal from said comparator circuit means, to provide an error signal; driver means for controlling said operating voltage in response to said error signal.
Claim 8
Dependent Claim
25 words
An output waveform control circuit as claimed in claim 5, wherein said driver means comprises a Darlington circuit including an NPN and a PNP transistor.
Claim 9
Dependent Claim
45 words
An output waveform control circuit as claimed in claim 5 or 6, wherein said power amplifier means comprises a series of cascading amplifiers supplied with said input signal simultaneously with said operating voltage to provide an output waveform having gently sloped leading and trailing edges.
Claim 10
Independent Claim
100 words
A method of controlling an output waveform from a circuit comprising a power amplifier, said method comprising the steps of: amplifying an input signal with said power amplifier; detecting the envelope of the output signal of said power amplifier to produce a first signal; generating a second signal having gently sloped leading and trailing edges; comparing said first and second signals to generate an error signal; and controlling the operating voltage of said power amplifier in response to said error signal to produce at the output of said power amplifier said output waveform having gently sloped leading and trailing edges.
Claim 11
Independent Claim
100 words
A method of controlling an output waveform from a circuit comprising a power amplifier, said method comprising the steps of: amplifying an input signal with said power amplifier; detecting the envelope of the output signal of said power amplifier to produce a first signal; generating a second signal having gently sloped leading and trailing edges; comparing said first and second signals to generate an error signal; and controlling the operating voltage of said power amplifier in response to said error signal to produce at the output of said power amplifier said output waveform having gently sloped leading and trailing edges.
Claim 12
Dependent Claim
30 words
A method as claimed in claim 8 further comprising, prior to said amplifying step, the step of controlling the level of said input signal in response to said error signal.
Claim 13
Independent Claim
107 words
An apparatus comprising: level control means for controlling the level of an input signal in response to an error signal; power amplifier means for amplifying the output of said level control means and controlling the level of the amplified signal in response to said error signal to produce a level-controlled signal; detector means for detecting the envelope of said level-controlled signal to produce an envelope signal; signal generator means for generating a control signal having gently sloped leading and trailing edges; and comparator means for comparing said envelope signal and said control signal to supply said error signal to said level control means and power amplifier means.
Claim 14
Independent Claim
107 words
An apparatus comprising: level control means for controlling the level of an input signal in response to an error signal; power amplifier means for amplifying the output of said level control means and controlling the level of the amplified signal in response to said error signal to produce a level-controlled signal; detector means for detecting the envelope of said level-controlled signal to produce an envelope signal; signal generator means for generating a control signal having gently sloped leading and trailing edges; and comparator means for comparing said envelope signal and said control signal to supply said error signal to said level control means and power amplifier means.
Claim 15
Dependent Claim
52 words
An apparatus as claimed in claim 10, wherein said level control means comprises: driving circuit means for producing a bias voltage and changing the level of said bias voltage in response to said error signal; and diode means for changing the level of said input signal in response to said bias voltage.
Claim 16
Dependent Claim
55 words
An apparatus as claimed in claim 10 or 11, wherein said power amplifier means comprises: driving circuit means for producing an operating voltage and changing the level of said operating voltage in response to said error signal; and amplifier circuit means for changing the level of said amplified signal in response to said source voltage.
Claim 17
Dependent Claim
15 words
An apparatus claimed in claim 12, wherein said driving circuit means comprises a Darlington circuit.
Claim 18
Dependent Claim
32 words
An apparatus claimed in claim 12 or 13, wherein said amplifier circuit means comprises a plurality of amplifiers connected in series at least one of which is driven with said source voltage.
Claim 19
Independent Claim
107 words
A method of controlling the levels of a modulated high-frequency signal, comprising the following steps of: level controlling said modulated high-frequency signal, in response to a first control signal, to produce a first smoothed signal; amplifying and level controlling said first smoothed signal, in response to a second control signal, to produce a second smoothed signal; detecting the envelope of said second smoothed signal to produce an envelope signal; generating a reference signal having gently sloped leading and trailing edges; comparing said envelope signal with said reference signal to produce an error signal; and producing said first and second control signals in response to said error signal.
Claim 20
Independent Claim
107 words
A method of controlling the levels of a modulated high-frequency signal, comprising the following steps of: level controlling said modulated high-frequency signal, in response to a first control signal, to produce a first smoothed signal; amplifying and level controlling said first smoothed signal, in response to a second control signal, to produce a second smoothed signal; detecting the envelope of said second smoothed signal to produce an envelope signal; generating a reference signal having gently sloped leading and trailing edges; comparing said envelope signal with said reference signal to produce an error signal; and producing said first and second control signals in response to said error signal.
References Cited (Backward Citations)
No citation records indexed.
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