Single Antenna Switching for RFID and Mobile Communication

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Solution Overview

Problem

The existing mobile terminals require separate antennas for RFID and mobile communication, leading to size enlargement due to the need for multiple antennas, which contradicts the trend of miniaturization in mobile terminal design.

Innovation Solution

A mobile terminal design that uses a single antenna with a switch and matching circuits (RFID and communication matching circuits) to selectively match the operating band to either the RFID or mobile communication frequency band, allowing both types of signals to be transmitted and received without the need for separate antennas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate antennas are provided for RFID and mobile communication, then both RFID and mobile communication functions can be implemented, but the mobile terminal size increases

Engineering Contradiction:

ImproveRFID and mobile communication functionalityVSAvoidmobile terminal size

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent combines RFID antenna and mobile communication antenna into a single shared antenna structure. The antenna is designed to operate at multiple frequency bands (908.5-914 MHz for RFID and 800 MHz for mobile communication) by using a matching circuit that can switch between different impedance values to match the antenna to different frequency bands, thereby eliminating the need for separate antennas and reducing terminal size.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single antenna is designed to serve multiple functions by supporting both RFID operations (908.5-914 MHz band) and mobile communication (800 MHz band). The matching circuit enables the antenna to be universally applicable to both frequency bands through impedance transformation, allowing one antenna to perform the work of two separate antennas.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a narrow band mobile communication antenna is used, then mobile communication performance is optimized, but RFID signal transmission and reception become difficult

Engineering Contradiction:

Improvemobile communication performanceVSAvoidRFID signal compatibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the electrical parameters of the antenna system by introducing a matching circuit with switchable impedance values. The matching circuit transforms the antenna's input impedance to match different frequency bands (908.5-914 MHz for RFID, 800 MHz for mobile communication), allowing the same physical antenna structure to operate reliably across different frequency bands by adjusting its electrical characteristics.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The matching circuit acts as an intermediary between the single antenna and the different frequency bands. It mediates the impedance mismatch between the antenna and the RFID/mobil e communication circuits, enabling efficient signal transmission in both frequency bands without requiring separate antennas optimized for each band.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 design miniaturizes the mobile terminal by enabling the use of a single antenna for both RFID and mobile communication signals, improving communication efficiency and maintaining compactness.

Implementation Method 1

an RFID matching circuit for changing an operating band of the antenna to a frequency band where a radio frequency identification (RFID) radio signal is input and output

Methodology Applied

Scientific EffectElectromagnetic resonance: Resonance

Implementation Method 2

a communication matching circuit which is disposed between the antenna and the communication module wherein the communication matching circuit matches the operating band of the antenna to a frequency band of the mobile communication radio signal

Methodology Applied

Scientific EffectImpedance matching:

Data Source

PatentUS7706834B2Mobile terminal having radio frequency identification (RFID) function

Publication Date: 2010.04.27 SAMSUNG ELECTRONICS CO LTD

AI summary

A mobile terminal is provided having an radio frequency identification (RFID) function and includes an antenna which transmits and receives a radio signal; a radio frequency identification matching circuit which changes an operating band of the antenna to a frequency band where an RFID radio signal is input and output; a communication module which processes a mobile communication radio signal transmitted and received via the antenna; and a switch which connects the antenna to either the communication module or the RFID matching circuit according to whether an RFID function is used or not. Accordingly, the compactness of the mobile terminal can be realized, and the RFID communication performance can be enhanced.