An electrosurgical generator includes a radio frequency output stage configured to output at least one radio frequency waveform and a sensor for sensing current. The sensor includes a current sensor coil having: an outer coil, an inner coil coupled to and disposed within the outer coil, and at least one shielding member disposed over the outer coil. Each of the at least one shielding member and the outer coil define an opening therethrough. The generator also includes at least one active lead coupled to the radio frequency output stage and passing through the current sensor coil. The current sensor coil is configured to output a signal indicative of a current within the at least one active lead.