Patent US4669464A successfully refreshed from Google Patents.
EP0503718A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Power amplifier and transmitting apparatus including such a power amplifier
Assignee: Philips Electronics UK Ltd
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Filing: 1992-03-04
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Granted: —
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Expires: 2012-03-04
Abstract
Abstract A power amplifier suitable for use in TDD and TDMA systems in which burst transmissions have to conform to a time mask, comprises a power amplifier (10) having a signal input (11), a signal output (14) and a control voltage input (24). A r.f.feedback control loop is coupled between the signal output (14) and the control voltage input (24). The control loop includes detection means (18) coupled to a comparison means (22) in which the detected signal is compared with reference pulses produced by a generating means (28). The output of the comparison means is coupled to the control voltage input (24). In order to provide a control signal when the output power level is too low to be detected, an artificial detector (38) is connected between the output of the comparison means (22) and its input for the detected signal in order to feed back the control voltage. As a result the control voltage versus power output characteristic is extended which leads to the generation of less transient sidebands and interference.
Inventors
- 👤 Martin Claydon
- 👤 Jonathan Charles Griffiths
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 00:22
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3036; H03G3/3042; H03G3/3047; H04; H04W; H04W52/00; H04W52/04; H04W52/06; H04W52/08; H04W52/18; H04W52/22
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
130 words
A power amplifier arrangement comprising a power amplifier having a signal input, a signal output and an input for a control voltage, a r.f. feedback control loop coupled between the signal output and the control voltage input of the power amplifier, the feedback control loop including detection means and comparison means for providing the control voltage in response to comparing an input signal with a reference signal, and means for feeding back a portion of the control voltage to an input of the comparison means, whereby at output power levels below that which are detectable by the detection means, the power amplifier is not subject to r.f. feedback control which changes to predominantly r.f. feedback control at output power levels which are detectable by the detection means, and vice versa.
Claim 2
Dependent Claim
17 words
A power amplifying arrangement as claimed in claim 1, characterised in that said means comprises amplifying means.
Claim 3
Dependent Claim
40 words
A power amplifying arrangement as claimed in claim 1, characterised in that said means comprises a potential divider coupled to the output of the comparison means for feeding back a predetermined portion of the control voltage to the comparison means.
Claim 4
Dependent Claim
94 words
A power amplifying arrangement as claimed in claim 1, characterised in that the detection means comprises an operational amplifier having means connected to its inverting input for setting the gain, and a junction of series connected first and second diodes coupled to its non-inverting input, in that the first and second diodes are in the same physical package and in that biasing means are provided for forward biasing the first and second diodes so that the voltage drop across each of the first and second diodes remains substantially equal irrespective of the ambient temperature.
Claim 5
Dependent Claim
134 words
A power amplifier arrangement comprising a power amplifier having a signal input, a signal output and an input for a control voltage, and a r.f. feedback control loop comprising means for deriving a signal indicative of the power amplifier output, detection means for detecting the signal derived by said means, comparison means having a first input coupled to an output of the detection means, a second input for connection to a reference signal producing means and an output coupled to the control voltage input of the power amplifier, and means having an input coupled to the output of the comparison means and an output coupled to the first input of the comparison means for feeding back a portion of the control voltage supplied in use to the control voltage input of the power amplifier.
Claim 6
Dependent Claim
71 words
A power amplifying arrangement as claimed in claim 5, characterised in that said means comprises an operational amplifier having a similar gain/bandwidth characteristic as the comparison means, in that a non-inverting input of the operational amplifier is coupled to the signal path between the output of the comparison means and the input for the control voltage, and in that an output of the operational amplifier is coupled to the comparison means.
Claim 7
Dependent Claim
37 words
A power amplifying arrangement as claimed in claim 6, characterised in that a potential divider is connected to the output of the operational amplifier and a tap of the potential divider is coupled to the comparison means.
Claim 8
Dependent Claim
40 words
A power amplifying arrangement as claimed in claim 5, characterised in that said means comprises a potential divider coupled to the output of the comparison means for feeding back a predetermined portion of the control voltage to the comparison means.
Claim 9
Dependent Claim
94 words
A power amplifying arrangement as claimed in claim 5, characterised in that the detection means comprises an operational amplifier having means connected to its inverting input for setting the gain, and a junction of series connected first and second diodes coupled to its non-inverting input, in that the first and second diodes are in the same physical package and in that biasing means are provided for forward biasing the first and second diodes so that the voltage drop across each of the first and second diodes remains substantially equal irrespective of the ambient temperature.
Claim 10
Dependent Claim
133 words
A transmitting apparatus including a power amplifier arrangement comprising a power amplifier having a signal input, asignal output and an input for a control voltage, a r.f. feedback control loop coupled between the signal output and the control voltage input of the power amplifier, the feedback control loop including detection means and comparison means for providing the control voltage in response to comparing an input signal with a reference signal, and means for feeding back a portion of the control voltage to an input of the comparison means, whereby at output power levels below that which are detectable by the detection means, the power amplifier is not subject to r.f. feedback control which changes to predominantly r.f. feedback control at output power levels which are detectable by the detection means, and vice versa.
References Cited (Backward Citations)
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