Dear all, as you can see in the high frequency square wave (maybe 100kHz) inverter that I saw online, the 4 mosfet they used is IRF 3205 and its datasheet here. I have tried to attach a high frequency square wave between the Gate and Source of the Mosfet, however all I got was a sawtooth wave which I saw. Furthermore, when I attach a resistor between the Gate and Source of Mosfet together with mosfet and I remove the Mosfet, I saw a very very good square wave (100kHz) on the resistor. I believe the problem is with the mosfet. Are there any ways to solve this issue that is to produce a good square wave (100KHZ) on the Gate-Source of this IRF 3205 mosfet that i bought which is used in high frequency inverter. I am pretty surprised it didnt work because these mosfet is used in high frequency inverter.