0
\$\begingroup\$

What happens if a MOSFET (n type) is used for the output of a 100 MHz oscillator for the pins G and S from my knowledge MOSFET uses voltage in Gate to control the Drain and Source current unlike a transistor which uses current for Base and Emitter to control current in Collector and Emitter.

Since MOSFET's G and S acts as a capacitor in which allows AC to pass throw for example IRF830 which has Total Gate Charge of 22 nC also Gate-Threshold Voltage of 4 V will it oscillate with the 100 MHz oscillation and oscillate the D and S current with a load (Hoping to put a tungsten blub there)?

My circuit diagram

enter image description here

R6 needs to be adjusted so that the G and S capacitor oscillates within the Gate Threshold range

Also when a very small tungsten blub (X-mas decoration type blub) is connected to the output of the 20 nf capacitor to ground it glows faintly. MOSFET and R6 R7 is not connected yet to the circuit. When I search the web everyone uses transistor to amplify the RF power but I don't have any high frequency power transistors and I don't like TO5 type transistors they are so hard to make a heat sink.

\$\endgroup\$
7
  • \$\begingroup\$ Your circuit won't work. Check the MOSFET connections. Why would you want to power a tungsten bulb with 100 MHz? \$\endgroup\$
    – Andy aka
    Commented Aug 31, 2021 at 10:38
  • \$\begingroup\$ Yeah I made a mistake I will fix it now \$\endgroup\$
    – Avon97
    Commented Aug 31, 2021 at 10:41
  • \$\begingroup\$ To check if its working for not so that D and S is oscillating \$\endgroup\$
    – Avon97
    Commented Aug 31, 2021 at 10:45
  • \$\begingroup\$ Note that between C3 and Q3 gate, there is nothing to bias the gate voltage. Sure, AC can pass to it, but without some form of bias, it could float anywhere between cut-off and saturation. \$\endgroup\$
    – rdtsc
    Commented Aug 31, 2021 at 12:04
  • 2
    \$\begingroup\$ First work out the current it takes to charge 22 nC 100 million times per second... \$\endgroup\$
    – user16324
    Commented Aug 31, 2021 at 12:53

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.