US5913154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
VSWR control technique for terminal products with linear modulation
Assignee: Unwired Planet LLC
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Filing: 1997-04-18
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Granted: 1999-06-15
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Expires: 2017-04-18
Abstract
Abstract A method for improving linear modulation compensation at the antenna terminals of an RF device in order to react to high voltage standing wave ratio variations is disclosed. In the present RF transmitters, such as portable radios, when transmission voltage standing wave ratio varies such that the linearization of its modulation technique is adversely affected, the dynamic accommodation of the variations in voltage standing wave ratio can be imposed on the output of the RF power amplifier to ensure that linearization is not lost. Specifically, the reverse power signal from the power amplifier can be detected and used to calculate a standing wave control signal. The standing wave control signal is provided to a step attenuator which attenuates the output of the power amplifier in an amount commensurate with the amount of reverse power signal at the output of the power amplifier. By adding attenuation in response to increases in reverse power signal, the linearity of the modulation being used can be controlled.
Inventors
- 👤 Stephen R. Wynn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:33
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/32; H04L27/34; H04L27/36; H04L27/366; H04L27/367; H04L27/368; H03; H03F; H03F1/00; H03F1/34; H03F1/56; H03F3/00; H03F3/20; H03F3/24; H04B; H04B1/00; H04B1/02; H04B1/04; H04B2001/0408; H04B2001/0433
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
76 words
An RF device, comprising: a modulator; an RF power amplifier connected to the modulator; a directional coupler for detecting a reverse power signal at an output of the power amplifier, the reverse power signal identifying any power reflected into the power amplifier; a standing wave controller for creating a standing wave control signal from the reverse power signal; an attenuator for attenuating an output signal from the power amplifier based on the standing wave control signal.
Claim 2
Dependent Claim
76 words
An RF device, comprising: a modulator; an RF power amplifier connected to the modulator; a directional coupler for detecting a reverse power signal at an output of the power amplifier, the reverse power signal identifying any power reflected into the power amplifier; a standing wave controller for creating a standing wave control signal from the reverse power signal; an attenuator for attenuating an output signal from the power amplifier based on the standing wave control signal.
Claim 3
Dependent Claim
53 words
An RF device according to claim 1, further including: a feedback loop connected from the output of the power amplifier to an input of the modulator; the directional coupler also for detecting a forward power signal at the output of the power amplifier and providing the forward power signal to the feedback loop.
Claim 4
Dependent Claim
16 words
An RF device according to claim 2, wherein: the feedback loop is a Cartesian feedback loop.
Claim 5
Dependent Claim
52 words
An RF device according to claim 1, further including: a terminal characterized by an output impedance; an antenna connected at the terminal and characterized by an antenna impedance; and wherein the reverse power signal detected by the directional coupler is indicative of any difference between the antenna impedance and the output impedance.
Claim 6
Dependent Claim
27 words
An RF device according to claim 1, wherein: the attenuator maintains the output signal at a level the impedes the modulator from operating in a non-linear manner.
Claim 7
Dependent Claim
15 words
An RF device according to claim 1, wherein: the modulator employs an amplitude variable carrier.
Claim 8
Dependent Claim
122 words
A radio transceiver, comprising: a modulator employing a linear modulation technique to provide a modulated signal; an RF power amplifier connected to receive the modulated signal and amplify it to an amplified signal; an attenuator connected to receive the amplified signal and attenuate it in accordance with a standing wave control signal; a directional coupler connected between the power amplifier and the attenuator to detect a forward power signal and a reverse power signal at an output of the power amplifier; a standing wave controller connected to receive the reverse power signal and to create therefrom the standing wave control signal; and a feedback loop connected to receive the forward power signal and to provide therefrom a feedback signal to the modulator.
Claim 9
Dependent Claim
122 words
A radio transceiver, comprising: a modulator employing a linear modulation technique to provide a modulated signal; an RF power amplifier connected to receive the modulated signal and amplify it to an amplified signal; an attenuator connected to receive the amplified signal and attenuate it in accordance with a standing wave control signal; a directional coupler connected between the power amplifier and the attenuator to detect a forward power signal and a reverse power signal at an output of the power amplifier; a standing wave controller connected to receive the reverse power signal and to create therefrom the standing wave control signal; and a feedback loop connected to receive the forward power signal and to provide therefrom a feedback signal to the modulator.
Claim 10
Dependent Claim
15 words
A radio transceiver according to claim 7, wherein the modulation technique is phase shift keying.
Claim 11
Dependent Claim
14 words
A radio transceiver according to claim 7, wherein the attenuator is a step attenuator.
Claim 12
Dependent Claim
16 words
A radio transceiver according to claim 7, wherein the feedback loop is a Cartesian feedback loop.
Claim 13
Dependent Claim
15 words
A radio transceiver according to claim 7, wherein: the modulator employs an amplitude variable carrier.
Claim 14
Dependent Claim
31 words
A radio transceiver according to claim 7, wherein: the attenuator adjusts the output of the power amplifier to a level that the impedes the modulator from operating in a non-linear manner.
Claim 15
Independent Claim
72 words
A method of transmitting an input signal, comprising the steps of: modulating the input signal using a linear modulation technique; amplifying the modulated input signal in a RF power amplifier; detecting a reverse power signal identifying reflected power at an output of the power amplifier; creating a standing wave control signal based on the reverse power signal; attenuating the signal obtained in the amplifying step based on the standing wave control signal.
Claim 16
Independent Claim
72 words
A method of transmitting an input signal, comprising the steps of: modulating the input signal using a linear modulation technique; amplifying the modulated input signal in a RF power amplifier; detecting a reverse power signal identifying reflected power at an output of the power amplifier; creating a standing wave control signal based on the reverse power signal; attenuating the signal obtained in the amplifying step based on the standing wave control signal.
Claim 17
Dependent Claim
35 words
A method according to claim 13, further including the step of: detecting a forward power signal at the output of the power amplifier; and feeding back a feedback signal derived from the forward power signal.
Claim 18
Dependent Claim
17 words
A method according to claim 14, wherein the step of feeding back employs a Cartesian feedback technique.
Claim 19
Dependent Claim
26 words
A method according to claim 13, wherein the step of detecting includes the step of providing a directional coupler at the output of the power amplifier.
Claim 20
Dependent Claim
18 words
A method according to claim 13, further including the step of: transmitting the attenuated signal using an antenna.
Claim 21
Dependent Claim
24 words
A method according to claim 13, wherein the step of attenuating includes the step of maintaining the modulation technique in a linear operating mode.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2002-06-14 | 2002-12-14 | 2003-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-06-14 | 2006-12-14 | 2007-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-06-14 | 2010-12-14 | 2011-06-15 | $7700.00 | Window Closed / Lapsed |