How to Make Radio Amplifiers More Efficient
This patent describes a method for tuning radio frequency power amplifiers to boost their efficiency and maintain a stable signal phase, especially when handling signals with changing loudness and direction.
Original patent title: “Efficient linear LINC power amplifier”
This patent describes a method for tuning radio frequency power amplifiers to boost their efficiency and maintain a stable signal phase, especially when handling signals with changing loudness and direction. Granted to NXP BV in 2012 with 16 claims and 4 forward citations, and it is expected to expire in 2029.
Coverage
What does this patent actually cover?
This patent details a method for optimizing radio frequency (RF) power amplifiers, which are crucial for transmitting signals. The amplifier has two main parts, called amplification branches, that work together. Each branch uses switching-mode amplification devices that can be turned on and off very quickly, controlled by a 'duty-cycle' (how long they are on versus off). The method involves carefully setting up the components in the combination circuit, specifically 'reactive inductive components,' to ensure the amplifiers switch on only when their voltage is near zero. This is called zero-voltage switching and helps reduce energy loss. Additionally, the patent explains how to adjust the duty-cycles of both branches. By sweeping through different 'out-phasing angles' (a way of controlling the signal's phase) and monitoring the output signal's phase and the amplifier's efficiency, the system can find the optimal duty-cycle settings. This ensures the output signal's phase stays consistent relative to the out-phasing angle, leading to a more linear and efficient amplification. For example, when amplifying a signal that changes in loudness and phase, this method fine-tunes the amplifier's settings to deliver the signal cleanly without wasting power.
The gap
What does this patent NOT cover?
- Amplifiers that do not use an out-phasing configuration.
- Amplifiers that do not have at least two amplification branches.
- Methods that do not involve adjusting the duty-cycle of the amplification devices.
- Methods that do not aim to maintain a constant phase of the output signal.
- Amplifiers that do not use switching-mode amplification devices.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The innovation lies in precisely tuning the 'duty-cycle' of the switching amplifiers in relation to the 'out-phasing angle' to achieve both zero-voltage switching for efficiency and constant output phase for signal integrity. This dual optimization, especially by sweeping parameters and monitoring results, was a key step in improving linear amplification techniques.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Modern smartphone radios
Cellular base station transmitters
Wi-Fi chipsets
Radio transmitters for various wireless communication systems
Why it matters
The bigger picture
Efficient power amplifiers are essential for all wireless communication devices, from smartphones to base stations. This patent addresses a core challenge in RF amplifier design: balancing signal quality (linearity, phase stability) with energy efficiency. By optimizing these parameters, it contributes to longer battery life in mobile devices and reduced energy consumption in communication infrastructure, which is critical as data traffic continues to grow.
Filed
April 30, 2009
Granted
September 18, 2012
Market context
Who's building on this
Companies in this space
NXP Semiconductors, the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, is a major player in automotive and mobile semiconductor solutions, including RF power amplifiers. Companies involved in designing and manufacturing wireless communication chips and systems, such as Qualcomm, Broadcom, and Skyworks Solutions, likely implement similar optimization techniques in their products.
Market impact
This patent, and the technology it describes, contributes to the ongoing drive for higher efficiency in RF power amplifiers. Such improvements are critical for meeting the demands of 4G and 5G mobile networks, enabling devices to transmit signals more effectively while consuming less power. This directly impacts the performance and battery life of countless consumer electronics.
Claim 1 — Plain English
What this patent covers
This patent details a method for optimizing radio frequency (RF) power amplifiers, which are crucial for transmitting signals. The amplifier has two main parts, called amplification branches, that work together. Each branch uses switching-mode amplification devices that can be turned on and off very quickly, controlled by a 'duty-cycle' (how long they are on versus off). The method involves carefully setting up the components in the combination circuit, specifically 'reactive inductive components,' to ensure the amplifiers switch on only when their voltage is near zero. This is called zero-voltage switching and helps reduce energy loss. Additionally, the patent explains how to adjust the duty-cycles of both branches. By sweeping through different 'out-phasing angles' (a way of controlling the signal's phase) and monitoring the output signal's phase and the amplifier's efficiency, the system can find the optimal duty-cycle settings. This ensures the output signal's phase stays consistent relative to the out-phasing angle, leading to a more linear and efficient amplification. For example, when amplifying a signal that changes in loudness and phase, this method fine-tunes the amplifier's settings to deliver the signal cleanly without wasting power.
The clever bit
The innovation lies in precisely tuning the 'duty-cycle' of the switching amplifiers in relation to the 'out-phasing angle' to achieve both zero-voltage switching for efficiency and constant output phase for signal integrity. This dual optimization, especially by sweeping parameters and monitoring results, was a key step in improving linear amplification techniques.
What it does not cover
- Amplifiers that do not use an out-phasing configuration.
- Amplifiers that do not have at least two amplification branches.
- Methods that do not involve adjusting the duty-cycle of the amplification devices.
- Methods that do not aim to maintain a constant phase of the output signal.
- Amplifiers that do not use switching-mode amplification devices.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Early stage
Citation count
14/40
Early citations
Claim breadth
11/20
Broad claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
5/20
Granted 10–20 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$22K – $70K
Midpoint $44K · 2.8 yr remaining · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Patent Claims
0 independent claims · 1 dependent
Claims are the legal boundaries of the patent. An independent claim stands alone. A dependent claim adds limitations to its parent, narrowing — but not broadening — the scope.
The original legal language
Original claims
16 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Vromans, J. S., Heijden, M. P. V. D., Graaw, A. J. M. D., & Jos, R. (2012). How to Make Radio Amplifiers More Efficient (U.S. Patent No. 8,269,555). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/8269555/efficient-linear-linc-power-amplifier
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How to Make Radio Amplifiers More Efficient cover?
This patent describes a method for tuning radio frequency power amplifiers to boost their efficiency and maintain a stable signal phase, especially when handling signals with changing loudness and direction.
Who owns patent US 8269555?
NXP BV owns this patent, granted in 2012.
When does this patent expire?
This patent is expected to expire on April 30, 2029, when the invention enters the public domain.
What is patent US 8269555 cited by?
This patent has been cited by 4 later patents that build on its ideas.
What problem does this patent solve?
Efficient power amplifiers are essential for all wireless communication devices, from smartphones to base stations. This patent addresses a core challenge in RF amplifier design: balancing signal quality (linearity, phase stability) with energy efficiency. By optimizing these parameters, it contributes to longer battery life in mobile devices and reduced energy consumption in communication infrastructure, which is critical as data traffic continues to grow.
What does this patent NOT cover?
Amplifiers that do not use an out-phasing configuration.
Patent monitoring