information about antenna design for contactless smartcard?
These are mostly inductive pickup. The manufacturer of the IC you use will have detailed information on the coil. This is because it has to have a very specific inductance for their IC system to work optimally.
Hi,
I was just wondering if these are similar to RFID?
Element7k
Are you talking 13.56Mhz contactless card or 900Mhz RFID?
Can anybody explain 13.56MHz cantactless application?
Smart cards are inductive pickup mostly at 13.56. They rectify the picked up field to power the electronics and then add an extra load of current which is sensed by the reader. The pulsed load is frequently a digitally modulated square wave carrier and well under 13.56. They use the 13.56 to synchronize the sending which makes the system optimum in that it is synchronous.
Smart cards once were contact, but the gold in the contacts added 1 euro to the price.
If you hold a card up to the light you can see the IC in the corner and the wire coil around the edges a few mm in.
yes, I mean 13.56MHz.
How is the difference between RFID and contactless technology?
If you are interested, here is a link for an article by James Rautio from Sonnet:
Electromagnetic Analysis Speeds RFID Design
This article, by Dr. James C. Rautio, describes how to use Sonnet to design Radio Frequency IDentification (RFID) tags. In this extremely competitive and dynamic market, getting the best and most innovative products to market before the competition is absolutely critical to survival. This paper shows how to use Sonnet for a complete and accurate analysis of the reader-coil pair in minutes, allowing dozens of designs to be considered in a single day.
This paper was first published in the February 2003 issue of Microwaves & RF magazine
hxxp://www.sonnetusa.com/support/downloads/publications/RFID.zip
(x=t)
You also can look for the original article in MWRF.
Search for appnotes at the chip manufacturers website (Temic/Atmel, EM Marin, etc)
regards, Al
for 13.56M contactless smartcard, the inductance, capacitance value and area of the coil are three importance parameters. These determine the power reception by the smartcard, care:
1. f0=1/(2*pi*(L*C)^1/2), this C include the parasitic capacitance of the antanna, package cap and the equivalent cap of IC input port.
2. because antenna of smartcard is often smaller than reader's antenna, more area, more mutual inductance, so more power transmitting.
I think this book must be very useful for you:
RFID Handbook : Fundamentals and Applications in Contactless Smart Cards and Identification
by Klaus Finkenzeller (Author)