I have an antenna/coil for an RFID application that I am resonating with a series capacitor. However, the current remains extremely low and does not agree with the calculated/theoretical values for its impedance. I am expecting high levels of current. See my setup below:
|Vo (Vpp)||Vc(Vpp)||Io (mArms)||Theoretical Io (Arms)|
*Operating frequency=125 kHz. Current was calculated using the voltage difference in Rs.
Do you have any idea of what I am missing to consider? I have tried reducing the parasitic resistance of the coil further (using Litz wire) and got similar results. I have done some simulations and they show non consistent values of current that depend on the inductance value (?). I have designed lower inductance coils (50uH) with even worse results. Obviously, I have increased the input voltage, but this is impractical since I am looking for >10A input current. Still, the input impedance of the resonating circuit shouldn't be that large. Finally, I have also made a frequency sweep to find the optimal operating point. Any help or advice will be appreciated!