In the case of a loop antenna with uncompensated inductance, the magnetic field generated by the current in the antenna is in antiphase to the incoming magnetic field of the EM wave. So it is believable that the current which causes cancellation of the flux through the antenna is the maximum current that you can draw. But in the case of a resonant antenna, there is 90 degrees phase shift between the magnetic field generated by the current in the antenna and the magnetic field of the incoming EM wave. In the idealized situation (no resistance, neglecting radiation by the receiving antenna) is there any limit on the current? (Or does it behave like I0*t*sin(2*Pi*f*t) if the induced voltage is U0*sin(2*Pi*f*t) ?).