13.56 MHz RFID Long Range Reading

[MichaelV]

Hello,

I am using a very small transponder operating at 13.56 MHz. I'd post the link if I could, but the company is Nonatec.net and they don't specify any ISO standard. Specs: Size: 1mm dia * 6 mm long, Weight: 7,15 mg, Operating frequency: 13,56 MHz

The read range with their reader is about 1cm.

Is there any way I can improve this by using a long range reader with a big antenna? Is the reading range inherent in the chip?

Thanks in advance for the help, I'm an RFID newbie so let me know if I need to provide more information.

Michael

 

[flatulent]

The best way is to use larger diameter coils on both ends of the link.

 

[MichaelV]

The best way is to use larger diameter coils on both ends of the link.

Thank-you for the reply, but I don't really know what that means. Could you explain?

Thanks,

Michael

 

[FvM]

The manufacturer is referring to a NXP Mifare chip, in other words, the implemented standard is ISO/IEC14443 A.

Of course, the only available option in your case is increasing the reader coil size. But the tag coil is obviously very small, so you won't achieve a large operation distance, even with a large reader coil. Besides field strength at the tag, receiving a sufficient load modulation signal is the second problem. As a first step, the required field strength and available tag signal, that are probably below ISO 14443 standard requirements, would be determined in a measurement.

 

[MichaelV]

The manufacturer is referring to a NXP Mifare chip, in other words, the implemented standard is ISO/IEC14443 A.

Of course, the only available option in your case is increasing the reader coil size. But the tag coil is obviously very small, so you won't achieve a large operation distance, even with a large reader coil. Besides field strength at the tag, receiving a sufficient load modulation signal is the second problem. As a first step, the required field strength and available tag signal, that are probably below ISO 14443 standard requirements, would be determined in a measurement.

That helps a bit more, but I'm totally new to this and don't fully understand the terminology.

What is "load modulation"? Why is it a problem?

What would be determined in a measurement?

Thank-you in advance,

Michael

 

[FvM]

Load modulation is the method for tag-to-reader communication. The tag is modulating the power consumed from the field, e.g. by switching a load resistance. Thus, the transmitted power is restricted to a fraction of the received power at the tag. It's pretty low for a < 1 mm diameter coil.

You can measure the minimal field strength required for operating the tag (= getting a response telegram) and the field strength of this response. It can possibly be done with a ISO/IEC 14443 A or multistandard reader and a sense coil (a wire loop) and an oscilloscope to measure the signals.