A method for pulse width modulation of a signal

Simple SummaryContent extracted from patent full text and abstract with AI.

This patent describes a method and transmitter design for improved pulse width modulation (PWM), where an input signal is upconverted, phase-shifted, and modulated using at least one PWM to generate two binary (2-level) signals. The relative phase difference between these two signals depends on the amplitude of the original input. By combining these signals, a 3-level PWM signal is produced, allowing for efficient amplification and reconstruction of the original analog signal. The invention dramatically increases coding efficiency, reduces noise, and simplifies implementation compared to conventional 2-level PWM systems—particularly for RF transmission applications such as wireless communication base stations.

Use CasesContent extracted from patent full text and abstract with AI.

• Power amplification for radio frequency (RF) transmitters in wireless communication base stations (e.g., cellular/mobile networks).
• High-efficiency transmitters in various wireless applications, including Wi-Fi, satellite, and broadcast.
• Efficient switching amplifiers for audio systems, such as class D audio amplifiers.
• Motor control systems requiring efficient and precise signal amplification.
• DC-DC power converters and power supply regulation with reduced noise and higher efficiency.
• LED brightness control and lighting systems using high-fidelity modulation.

BenefitsContent extracted from patent full text and abstract with AI.

• Significantly higher coding efficiency (above 60%) compared to conventional PWM techniques (~12%), leading to more power at the desired carrier frequency.
• Reduced quantization noise and cleaner signal spectra, resulting in relaxed filter requirements and better signal quality.
• Enables the use of highly efficient switching power amplifiers, minimizing power loss and heat generation.
• Simpler signal processing structure, making hardware implementation easier and more robust.
• Phase modulation with near-constant duty cycles leads to better compatibility with switching components and reduced electromagnetic interference (EMI).
• Scalable to multi-level systems for further improvements in efficiency and performance.

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Patent Abstract

The invention concerns a method for pulse width modulation of an input signal (SBB) using at least one pulse width modulator (PWM1, PWM2), wherein the input signal (SBB) is upconverted on a carrier frequency, phase shifted and pulse width modulated in said at least one pulse width modulator (PWM1, PWM2) resulting in a first and a second phase shifted pulse width modulated signal with two levels (SPSPWM1, SPSPWM2), said first and second phase shifted pulse width modulated signal with two levels (SPSPWM1, SPSPWM2) have a phase difference (2”) which is dependent on the amplitude of the input signal (SBB), and a superposition of said first and second phase shifted pulse width modulated signal with two levels (SPSPWM1, SPSPWM2) results in a signal with three levels (SPWM), and a transmitter therefor.