Close identification project

[Pekari]

Hi!

My next project is to make tiny, without battery working device (an example coil and capacitor = resonance circuit) which can detect ~1 m distance. (An example 1 bit RFID device).

And this circuit which detecting the tiny circuit is my problem. I have try it with few circuit but without lucky.

Does someone have a experience or an example on this kind of project?

I have try to search a threads but no lucky.

 

[KeithRB]

I am not sure what you are doing here, but store theft detectors use diodes (that are easily burnt out) as frequency doublers. Put a signal into the device and 2*freq comes back. The sensing device needs power, but the sensed device does not.

 

[Pekari]

Thanks!

I need to add more power o the sender coil. Now senced device voltage is 10mV and it need to be over 0,3V? (if I use schottky diode.)
Is that diode in serial or parallel with coil and capacitor?

 

[Pekari]

Does anyone have experience this kind of technology?

Is coil and diode enough inside of identification device?