RFID Reader Doppler Signal Detection Circuitry

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current RFID systems cannot effectively track the movement and speed of items within an interrogation zone due to the lack of necessary hardware or logic to detect Doppler signals, requiring additional hardware like PIR detectors, which increases costs and complexity.

Innovation Solution

Incorporating Doppler signal detection circuitry into existing RFID readers to process Doppler signals and determine the relative movement, direction, and speed of items within the interrogation zone, utilizing existing RFID hardware without the need for additional components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate Doppler signal detectors are incorporated into the RFID system, then the system can detect movement and speed of items, but the cost, labor and design complexity increase

Engineering Contradiction:
Improvemovement detection capabilityVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the Doppler signal detection capability with the existing RFID reader hardware. The RFID reader is modified to include Doppler detection circuitry that processes the same RF signals it already transmits and receives, eliminating the need for separate Doppler detectors. This merging of functions reduces system complexity while maintaining movement detection capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The RFID reader is designed to perform multiple functions: traditional RFID identification and new Doppler-based movement detection. By making the RFID reader a multi-functional device that can both identify items and track their movement, the system avoids adding separate specialized hardware, thereby reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If PIR detectors are incorporated into the RFID system, then motion detection is enabled, but additional hardware and start up costs are required

Engineering Contradiction:
Improvemotion detection capabilityVSAvoidhardware quantity
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

Instead of adding separate PIR detectors, the patent merges motion detection functionality into the existing RFID reader. The RFID reader's RF signals are used to detect Doppler shifts caused by moving items, combining identification and motion detection in a single device without requiring additional sensors or hardware.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The RFID system uses its own transmitted RF signals to detect motion through Doppler shift analysis. The system serves itself by utilizing its existing electromagnetic field for dual purposes: RFID communication and motion detection, eliminating the need for external PIR detectors or additional sensing hardware.

Inventive Principle:
Principle #25Self-service

3Device complexity

If RFID readers filter out or ignore Doppler signals, then the system maintains simplicity, but movement tracking information is lost

Engineering Contradiction:
Improvesystem simplicityVSAvoidmovement information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent extracts the Doppler signal information from the RF signals already being processed by the RFID reader. Instead of filtering out these signals, the system separates and analyzes the Doppler shift components to extract movement data, while maintaining the simplicity of using only the existing RFID reader hardware.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables the RFID system to detect and process Doppler signals to determine item movement, direction, and speed, enhancing tracking capabilities without additional hardware, thus reducing costs and complexity while maintaining existing system functionality.

Implementation Method 1

The transmitting antenna, the transceiver and the decoder are often collectively referred to as the RFID reader. The RFID reader, which can be either a handheld or a fixed-mount device, emits radio waves in ranges of anywhere from one inch to 100 feet or more

Methodology Applied
Scientific EffectRadio wave transmission and reflection: Reflection

Implementation Method 2

The present invention relates to radio frequency identification (''RFID'') devices and more particularly to a system and method for monitoring the relative directional movement and speed of an article within an RFID interrogation zone by use of Doppler detection circuitry incorporated within an RFID surveillance system

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP2070001B1Radio frequency identification system with doppler detector
Publication Date: 2018.05.30 TYCO FIRE & SECURITY GMBH
  • EP2070001B1 patent drawingFigure 1~2
  • EP2070001B1 patent drawingFigure 3~4
  • EP2070001B1 patent drawingFigure 5

AI summary

A system and method for a radio frequency identification (RFID) reader for use in an RFID detection system. The reader has an RF source for generating RF signals. An antenna is coupled to the RF source. The antenna transmits interrogation RF signals to one or more RFID markers within an interrogation zone and receives communication signals from one or more items within the interrogation zone. The communication signals include Doppler signals indicating movement of an item within the interrogation zone. A receiver receives the communication signals and motion detection circuitry detects the Doppler signals.