RFID Industry Background

Applications for RFID systems are rapidly expanding as such systems find wide use in mobile equipment, such as cellular phones, RFID tags, non-contact IC cards, and more.
Market expansion is also predicted for such applications as access control systems for IT security and commodity distribution management systems for performing inspections and inventory checks.
However, RFID systems have a weakness of failure to communicate when there is a metal object present next to the antenna. A high-performance magnetic sheet that can solve this problem is needed.

Development Concept

The 13.56 MHz RFID system has a problem with communication failure when a metal object is nearby. By using the RFN series, it has now possible to use RF tags even over metal.

Feature: Its thinness (less than 0.1 mm) makes it ideal for compact mobile equipment. Feature: Realization of high μ' (approx. 45) and low μ'' (approx. 3) at 13.56 MHz makes it possible for an RFID system to communicate over a long distance. Feature: The roll format makes it easy to combine with other rolls (seals and labels). Feature: Halogen-free, ecological and compliant with RoHS directive

(Patent Number:3728320)

Communication experiment with 13.56 MHz band RFID system

Although communication distance in the free space is approximately 8 cm, any metal object in the vicinity of a tag will cause a communication failure. By using a 100 μm-thick magnetic sheet, a communication distance of up to 4 cm becomes possible even if a metal object is close by.

RFID Magnetic Sheet ● Improving antenna sensitivity for metal-resistant RFID tag (13.56 MHz) ● Improving communication distance from metal-resistance in Reader/Writer ● One or both cards can now be read when there are two non-contact IC cards to be read

Product Specification

Type Notation		RFN7	RFN8	RFN10
Characteristics		Sheet Type / Roll type
Frequency 　(MHz)		13.56
Permeability (13.56MHz)	μ'	46	32	45
	μ''	10	9	3
Thickness　(μm)		50 / 100
Surface Resistivity　(Ω/□)		Over 108		Over 104
Flame Retardant		UL94 V-0 level		Non flame retardant
Service Temperature Range　(°C)		-40 to +100		-40 to +60
Sheet Dimensions　(mm)		200 × 300 / 180 mm x 100 m Roll

* Please contact us regarding thickness and format.
* This product is not designed for use as a radio wave absorber.
* We strictly comply with Japan’s security and export control laws.
* Figures above shows the mean value and are not guaranted values.
* Roll width size ：(max) 360 mm in width

 

RFN series-Permeability dependent on frequency

Ordering Format

Sheet type example:
For [RFN7- 100μm thick, 200 mm x 300 mm size with 30 μm thick double-sided adhesive tape, half-cut available]

Roll type example:
For [RFN10-100 μm thick, 180 mm width x 100 m length with 30 μm thick double-sided adhesive tape]

Electromagnetic Wave Analysis

An example of electromagnetic wave analysis (for 13.56 MHz band RFID tag)

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<Tag Construction> ● Calculation results for the coupling characteristics between coil antennas ● In the free space, the tag and reader/writer resonate at 13.56 MHz. ● Where a metal object is present near a tag, the resonance frequency of the tag shifts greatly in the high frequency end. The graph shows that it shifted to approximately 28 MHz. The resonance frequency of the reader/writer remains at 13.56 Mhz. ● In this case, if a magnetic sheet is used near the tag as shown in the figure above, resonance frequency of the tag can approach 13.56 MHz. ● It is possible to optimize the resonance frequency and Q value of a tag antenna (coil) by selecting the proper magnetic permeability and thickness of a magnetic sheet.

<Result of electromagnetic analysis>

Basic Principle

Normal Communication Condition

RFID wireless communication becomes possible by magnetic flux penetrating between two coil antennas.

Communication Condition with a Metal Surface in the Vicinity

Eddy current occurs at the metal in the vicinity of a tag, caused by the Reader/Writer's magnetic field. This magnetic field (demagnetizing field) caused by the eddy current cancels the magnetic filed necessary for communication.

Communication Condition with a Magnetic Sheets Present