RFID Tag Positioning With Selectable Antennas and Fewer Receive Channels

Solution Overview

Problem

Conventional RFID systems with a large number of antenna elements and receive channels are complex and costly, and the use of phase shifters limits positioning distance and increases costs.

Innovation Solution

A positioning apparatus that selects combinations of antenna elements using an antenna selection circuit, reducing the number of receive channels and eliminating the need for phase shifters, while using a repeater to extend the positioning distance for passive RFID tags.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a large quantity of antenna elements and receive channels are used in the RFID positioning system, then positioning accuracy and positioning distance are improved, but system complexity and cost increase significantly

Engineering Contradiction:

Improvepositioning accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the receive channels into multiple groups, where each group is associated with a specific antenna element. This allows the system to process signals from multiple antenna elements while using fewer receive channels, thereby reducing system complexity while maintaining positioning accuracy through spatial diversity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent makes the receive channels multi-functional by enabling each receive channel to serve multiple antenna elements through the grouping mechanism. A single receive channel can process signals from different antenna elements at different time slots, reducing the total number of receive channels needed while maintaining the ability to accurately position tags.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If a large quantity of antenna elements and receive channels are used in the RFID positioning system, then positioning accuracy and positioning distance are improved, but system cost increases significantly

Engineering Contradiction:

Improvepositioning accuracyVSAvoidsystem cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent segments the receive channels into multiple groups, where each group is associated with a specific antenna element. This allows the system to process signals from multiple antenna elements while using fewer receive channels, thereby reducing system complexity while maintaining positioning accuracy through spatial diversity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent makes the receive channels multi-functional by enabling each receive channel to serve multiple antenna elements through the grouping mechanism. A single receive channel can process signals from different antenna elements at different time slots, reducing the total number of receive channels needed while maintaining the ability to accurately position tags.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Length of stationary object

If phase shifters are used in the RFID positioning system, then positioning distance is extended, but system cost and complexity increase

Engineering Contradiction:

Improvepositioning distanceVSAvoidsystem complexity

Core Design Contradiction:

Length of stationary objectVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the phase shifter component from the system by using an alternative approach based on signal timing and antenna element grouping. The positioning distance is extended through other means such as using multiple antenna elements for spatial diversity and improved signal reception, without requiring expensive phase shifters.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive phase shifters with simpler, lower-cost components such as antenna elements and signal processing circuits. The system achieves extended positioning distance through software-based signal processing and antenna array techniques rather than expensive hardware phase shifters.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces system complexity and cost, improves positioning accuracy, and extends the effective range of passive RFID tags to 100 meters without the need for phase shifters.

Implementation Method 1

an antenna array includes M×N antenna elements... receive an answer signal from the tag through L antenna elements selected by the antenna selection circuit

Methodology Applied

Scientific EffectElectromagnetic radiation reception: Electromagnetic Induction

Data Source

PatentUS12443809B2Positioning method, apparatus, and system

Publication Date: 2025.10.14 HUAWEI TECH CO LTD

AI summary

This application describes a positioning method, apparatus, and system. The positioning apparatus includes an antenna selection circuit, a receiving processing circuit, and a processor, and the antenna selection circuit is coupled to the processor through the receiving processing circuit. The antenna selection circuit is coupled to an antenna array that includes M*N antenna elements, and the antenna selection circuit selects different combinations of antenna elements from the antenna array, where each combination of antenna elements includes L antenna elements. The processor controls the antenna selection circuit to select a combination of antenna elements from the antenna array. The receiving processing circuit receives an answer signal from a tag through L antenna elements selected by the antenna selection circuit, and processes the answer signal. The processor then positions the tag based on processed data.