Problem with charging transponder of Tiris S2000 reader

If anyone here ever have this problem :

I've a couple of installations using Tiris S2000 reader with passive transponder.
Some sites have this problem :
Most of the day, the transponder can be charged and response within 1.5 meters, but for a few hours a day,this range fall to very low ,even 10mm from the antenna.
Then in the evening ,things go back to normal.
I suspect some machinery..eg fans etc is distturbing the low frequency of the Tiris (144Khz)
Synchronisation with nearby readers have been tried but little success to solve the problem above.

Does anyone have suggestions to counter-measure the disturbance? All equipment used are from TI. Anything to shift the freq. or boost..noise cancellation....help.
I'm brain-dead when dealing with antenna and RF stuff.


thks ..lak

my suggention is:
0 you may connect between tranponder and rfid card antenna input with hard wire. and check it.
you can identify outcomming jamming or internal curcuit error. if theres jam,
1 measure the jammer using field strength measurement equipment with dipole antenna.
2 if you can find undesired signal,you may search the original source of it. and stop the jumming signal.
3 if you cannot find the signal then you may check your curcuitry again.
that all i can suggest for you

Re: Help : Tiris Rfid

Hi,
There are some thing that is important in RFID range :

1- you are working near metal environment
2- there is a frequency interference near antenna
3- there is a fault with your antenna or circuit
4- the capacity which is placed in the tag is not tuned