RF Front-End Bias Calibration for Multi-Channel Beamforming

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Solution Overview

Problem

Existing RF communication systems face challenges in efficiently managing bias currents for amplifiers in multi-channel configurations, particularly in millimeter wave and 5G spectrums, which affect beamforming accuracy and efficiency.

Innovation Solution

A front-end system with integrated amplification chains, control circuits, and multiplexors on a single die, utilizing digital-to-analog converters and shared bias generators to manage bias currents, ensuring precise control and temperature compensation for amplifiers across multiple channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If separate bias current sources are used for each amplifier in multi-channel RF systems, then each amplifier can be independently controlled, but the device complexity and area increase significantly

Engineering Contradiction:

Improveindependent amplifier controlVSAvoidbias current management structure

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges multiple separate bias current sources into a single shared bias current source that serves multiple amplifiers across different channels. This consolidation reduces the overall number of bias current generators while maintaining the ability to independently control each amplifier through individual current mirrors, thereby resolving the contradiction between independent control and device complexity

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shared bias current source is designed to serve multiple functions and multiple channels simultaneously. A single bias current generator can provide bias currents to multiple amplifiers operating in different frequency bands (e.g., 5G NR bands), making the bias current management system universal and applicable across diverse RF communication scenarios

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple bias current sources are used for different frequency bands, then each band can be optimized independently, but the area and power consumption increase

Engineering Contradiction:

Improvefrequency band optimizationVSAvoidfront end system area

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent combines bias current sources for multiple frequency bands into a single shared resource. The shared bias current source can dynamically allocate and adjust bias currents to different amplifiers operating in various 5G NR bands, eliminating the need for separate dedicated bias current sources for each band and thereby reducing the overall system area

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The bias current management system employs dynamic control mechanisms where the shared bias current source can adaptively adjust the bias current distribution based on the operational requirements of different frequency bands. This dynamic allocation allows the system to maintain optimal performance across multiple bands without requiring static, dedicated bias sources for each band

Inventive Principle:

Principle #15Dynamics

3Measurement precision

If independent bias current control is implemented for each channel, then beamforming accuracy improves, but the device complexity and calibration difficulty increase

Engineering Contradiction:

Improvebeamforming accuracyVSAvoidbias current control structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the control functionality into a unified bias current management system that uses current mirrors to distribute and independently control bias currents to multiple amplifiers. This unified approach simplifies the control structure while maintaining the precision needed for beamforming applications, as the current mirrors ensure accurate current replication and distribution

Inventive Principle:

Principle #5Merging (Combining)

4Reliability

If separate bias current generators are used for each amplification chain, then temperature compensation can be optimized per chain, but the power consumption and area increase

Engineering Contradiction:

Improvetemperature stabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent combines multiple temperature compensation mechanisms into a single shared bias current source that serves multiple amplification chains. The shared source incorporates temperature sensing and compensation circuitry that can monitor and adjust the bias current for all connected amplifiers, providing temperature stability across the entire system without requiring separate compensation circuits for each chain, thereby reducing overall power consumption

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12407306B2Radio frequency front end with integrated channel matching calibration

Publication Date: 2025.09.02 SKYWORKS SOLUTIONS INC

AI summary

Radio frequency (RF) front ends with integrated channel matching calibration are provided herein. In one aspect, a front end system includes: a plurality of front end amplification chains including transmit and receive chains for at least two radio frequency bands, each of the front end amplification chains configured to either transmit or receive radio frequency signals via one of a plurality of antennas, and each of the front end amplification chains includes an amplifier configured to receive a bias current and amplify the corresponding radio frequency signal based on the bias current, a control circuit configured to generate each of the bias currents, and a multiplexor configured to receive the bias currents and provide the bias currents to the corresponding amplifiers.