Basic knowledge of RFID

RFID (radio frequency identification) is automatic recognition technology that uses wireless communication. Generally, a system or a part that uses an IC tag to identify or control various items via wireless communication is called RFID. Here, a description is given mainly of the features of RFID and the principle of wireless communication in order to provide basic knowledge concerning RFID.

Murata Icon X What is RFID

RFID (radio frequency identification) is automatic recognition technology that uses wireless communication. Generally, a system or a part that uses an IC tag to identify or control various items via wireless communication is called RFID. By using RFID, data can be written and read between points that do not touch each other, and also multiple sets of data can be read as a batch. Also, communication can be carried out over a distance of several meters, provided that the RFID reader/writer and the IC tag are located within the range over which radio waves can be transmitted. RFID is used in various fields as new automatic recognition technology which replaces barcodes and QR codes.

RFID communication is performed by radio waves transmitted between the reader and writer.

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Murata Icon X Features of RFID

RFID has various advantages compared to other kinds of automatic recognition technology, such as a barcode.


Data can be read at a
long distance

 

Multiple tags
can be read as a batch

Communication can be carried out over a long distance inside a warehouse.   Batch-reading of data from tags in a storefront backyard
     

By using wireless communication, data can be read at distance of several meters. Data can be easily read from a tag that is a long distance away, or from a tag that is in a high, relatively inaccessible place.

 

RFID obviates the need to hold each item one at a time in order to read the data. It enables the data in all of the tags to be to be read as a batch by simply passing the scanner over the tags. This greatly reduces the time required to carry out stocktaking, etc.

     

Data can also be read
from outside the box

 

Long life

Data can also be read from outside a cardboard box   An RFID tag can be used semi-permanently.
     

Because data is communicated by radio waves, it can be read from outside the packing box without any need to open the box, even when a tag is attached to the product. Also in case of barcode, it can not be read when the surface becomes soiled.  On the other hand, RFID is highly immune to dirt, and can read data without problem even if the surface of the target is dirty.

 

A passive type RFID tag can be used semi-permanently without any need for a battery. In addition, because the tag incorporates a memory, it also enables the data to be re-written. Compared to a barcode, RFID enables a large amount of data to be exchanged.


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Murata Icon X RFID frequency bands

RFID consists of four frequency bands, the LF band, HF band, UHF band, and microwave band, to be used. Murata’s RFID uses HF band and UHF band communication, and international compatibility is guaranteed by the ISO/IEC 18000 series wireless communication standards. Consequently our RFID is used in countries throughout the world.


・LF band
The LF (Low Frequency) band employs an electromagnetic induction method, and has a long history of use compared to other communication bands. The LF band is used for wireless communication in a keyless entry system for an automobile, etc. Although the communication distance is only several tens of centimeters, it is necessary to use a large number of windings on the antenna, making it difficult to fabricate a thin, compact antenna.

・HF band
The HF (High Frequency) band exchanges data using an electromagnetic induction method. Compared to the LF band, it does not require a large number of windings on the antenna, making it easy to fabricate a thin, compact antenna. Because the HF band uses 13.56 MHz, which is a frequency in the short wave band, the communication distance is relatively short, making the HF band suitable for applications in a proximity area, such as those in which persons and items are validated in a 1-to-1 ratio. An NFC (Near Field Communication) device, which is incorporated in electronic money, such as a wallet cellphone or a transportation card, also uses HF band RFID.

・UHF band
An electronics field type communication method is employed in the UHF (Ultra High-Frequency) band. The frequency range is between 860 and 960MHz, which is in the ultra-high frequency band, making the UHF band suitable for applications over a communication distance of several meters, such as those in which multiple sets of data are read simultaneously. Most stock control and automatic inspection is carried using this frequency band.

・Microwave band
The microwave band belongs to the UHF band, and the frequency used is 2.45 GHz. Because this band includes the ISM band, which is also used by microwave ovens and wireless LAN (Wi-Fi), there are concerns about radio wave interference. It is therefore necessary to take preventive measures. Also the communication distance is only 2 to 3 meters which is much shorter that of the band between 860 and 960 MHz.


Communication band LF HF/NFC UHF Microwave
Frequency to 135KHz 13.56MHz 860 to 960MHz 2.45GHz
Communication
method
Magnetic field communication Magnetic field communication Electronic field communication Electronic field communication
Communication range to 10cm to 10cm to several m to 3m
Directionality Wide Wide Medium Narrow
Effect of metal Medium Large Large Large
Effective of water Small Small Medium
Large
Application examples Keyless entry Public type IC card, security control Stock control, asset management, etc

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Murata Icon X Principle of RFID communication

Basically, RFID communication is performed by means of a battery-free passive tag which reflects carrier waves sent from the reader/writer.

Communication between the RFID reader/writer is shown in the diagram.


Flow of communication
1) Radio waves are transmitted from the reader/writer.
2) The antenna inside the IC tag receives radio waves from the reader/writer.
3) Current flows through the IC, converting the data in the chip into signals.
4) Signals are transmitted from the antenna which has electrodes printed on the IC tag side.
5) The antenna of the reader/writer receives signals returned from the antenna.
6) Data processing is performed by a PC via the reader/writer controller.

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Murata Icon X RFID solutions

RFID is used in a variety of areas for various applications. Here we will introduce  Murata’s RFID solutions (examples of introduction).

* You can access details of each item by clicking on it.

This is a link which provides a description of Murata's RFID solutions.

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