# 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. - **Patent:** US 8269555 - **Original title:** Efficient linear LINC power amplifier - **Owner:** NXP BV - **Granted:** 2012 - **Status:** Active - **Times cited:** 4 - **Field:** consumer_electronics, telecommunications, semiconductors ## What it does 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. ## 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. ## 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. ## Real-world examples 1. Modern smartphone radios 2. Cellular base station transmitters 3. Wi-Fi chipsets 4. Radio transmitters for various wireless communication systems ## Why it matters 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. ## 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. **Full plain-English explainer:** https://patentbrief.org/patent/us/8269555/efficient-linear-linc-power-amplifier **Original patent:** https://patents.google.com/patent/US8269555 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [Combining Radio Signals Efficiently with Special Wires](https://patentbrief.org/patent/us/9141832/multiway-lossless-power-combining-and-outphasing-incorporating-transmission-line) — MIT's 2015 patent describes a clever way to combine multiple radio signals using specific lengths of transmission lines to boost power efficiently and linearly. - [Designing Electronic Networks for Efficient Power Amplification](https://patentbrief.org/patent/us/6552634/wideband-minimum-rating-filters-and-multicouplers-for-power-amplifiers) — This patent describes how to design electronic networks that allow power amplifiers to work efficiently over a wide range of frequencies without overheating or failing. - [How Wireless Radios Automatically Adjust to Avoid Signal Overload](https://patentbrief.org/patent/us/12255678/falcon-1) — A method for wireless devices to automatically rearrange their internal signal-processing components when incoming radio signals are too strong and threaten to overwhelm the hardware. - [How Smartphones Calibrate Their Radio Power Across Different Temperatures](https://patentbrief.org/patent/us/8831529/airplay-wireless-streaming) — A method for testing and calibrating a phone's wireless radio performance in a temperature-controlled chamber to ensure it stays accurate as the device heats up or cools down. - [How Touchscreens Precisely Align Signals to Detect Your Touch](https://patentbrief.org/patent/us/8493330/individual-channel-phase-delay-scheme) — Apple's patent describes a way for touchscreens to adjust the timing of internal electrical signals so they perfectly match the signals coming from your finger, making touch detection more accurate.