Possible to send RFID data to reader using radio frequencies?

Thread Starter

boingaon

Joined May 15, 2012
31
I'm looking to track objects around my home and business using RFID tags and a reader. I want to be able to read the tags in the objects from a greater distance than the tags are capable.

As an experiment, I would like to make a special tag that transmits RFID information using an on-board power supply and transmitting antenna. (radio waves).

My question is, can RFID readers pick up radio wave signals is they are tuned to the same frequency that they are intended to read? (commonly 13.56MHz or 125kHz).

The readers function under the principle of electromagnetic induction, so I'm not sure about this.

If it wouldn't work, is there any way to boost the original tag using on-board power to extend the transmit range to about 10 feet?

Thanks
 

Thread Starter

boingaon

Joined May 15, 2012
31
Thank you, but I'm really looking to answer one important question - can a reader equipped with an inductive transmitter/receiver pick up signals from a tag that sends data using radio waves?

Or, another option would be to use a conventional inductive antenna on the tag, but power it up to improve the range.
 

thatoneguy

Joined Feb 19, 2009
6,359
How large would you want the tag?

A coin cell can send in pulses for short periods (think keyfob remote door locks).

It will need a sizeable amount of support circuitry, so that no power is drawn until triggered by the RFID field it is sending to.
 

WBahn

Joined Mar 31, 2012
30,082
I think you have a number of problems to contend with. As you say, most RFID is done inductively so essentially you have an air core transformer and what the reader is sensing is whether the load is light or heavy. So the reader is essentially sensing how much power the tag is pulling from it, synchronized to the reader's waveform. So your long-distance tags would have to mimick that effect. Now, I believe their are active RFID systems that would be more suitable for this.

Then, as tags get further away from each other you will have increased problems with self-jamming and the potential for hidden node problems.
 
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