Patent ID: 8847663

Claim:
A gate drive circuit which drives a gate terminal of a semiconductor switching device, the gate drive circuit comprising: a signal output port and a reference output port which constitute a terminal pair for outputting a signal for driving the gate terminal; a first wireless signal transmitter which receives a first high-frequency signal as an input, transmits the input first high-frequency signal wirelessly, and outputs the signal, the first high-frequency signal having been modulated and indicating a period during which the semiconductor switching device is ON; a second wireless signal transmitter which receives a second high-frequency signal as an input, transmits the input second high-frequency signal wirelessly, and outputs the signal, the second high-frequency signal having been modulated and indicating a period during which the semiconductor switching device is OFF; a first rectifier circuit which includes at least a first diode that rectifies the first high-frequency signal output from the first wireless signal transmitter to output to the signal output port a signal which has a voltage of a first polarity with respect to the reference output port; and a second rectifier circuit which includes at least a second diode that rectifies the second high-frequency signal output from the second wireless signal transmitter to output to the signal output port a signal which has a voltage of a second polarity with respect to the reference output port, the second polarity being opposite to the first polarity, wherein a threshold voltage of the second diode is larger than a threshold voltage of the first diode.