I don't understand why the inductor is placed in the gate of NMOS. Could anyone explain the reason for that?
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With AC signal, inductor behaves like a resistor, I only know this and get stuck hereWhat if the inductor weren't there?
What would the voltage on the gate be in response to an AC input signal?
Oh, sorry,I didn't notice. I don't see any problem if the inductor weren't there. VGS will bias for the transistor. Can you give some hints?My questions asked what if the inductor weren't there. If it's not there then it doesn't matter how it behaves.
With AC signal applied, then there is a fraction of input voltage drop in inductor.The second question IS the hint.
Without the inductor, both Vin and Vgs are connected to the gate with different voltage. Then how do you know the gate voltage is Vgs not Vin?You've basically got it. Without the inductor, the gate voltage is simply Vgs and the input signal can't affect it.
The AC would be shorted to ground in the bias source.What do you mean by short circuit?
I meant as the picture bellow. Vin and Vgs are connected to the gate and they have the different voltage.What do you mean by short circuit?
Can you explain why thre is no AC signal on the gate without the inductor?The AC would be shorted to ground in the bias source.
The inductor, or choke provides a high impedance to the AC source as well as providing a low resistance path for the gate bias voltage.
Without it there would be no AC signal on the gate.
I was actually hoping the OP would clarify this statement. Clearly you know what the answer is but the OP clearly doesn't.The AC would be shorted to ground in the bias source.
The inductor, or choke provides a high impedance to the AC source as well as providing a low resistance path for the gate bias voltage.
Without it there would be no AC signal on the gate.
Yes I can...Can you explain why thre is no AC signal on the gate without the inductor?
Thanks Sue.Yes I can...
There is no AC signal because the gate bias supply will shunt the AC to ground unless the bias is decoupled by some means a choke is not the only way to accomplish this you could also use a high value resistor. with the end connected to the gate bias source bypassed with a cap...
Sorry I wasn't up here earlier...
There are a number of ways of answer this question.Without the inductor, both Vin and Vgs are connected to the gate with different voltage. Then how do you know the gate voltage is Vgs not Vin?
And is there a short circuit that happens in this case?
At the end of the day a voltage source is a voltage source and at any moment in time the outputs combine via the properties of the circuit network connecting them to produce the voltage at any paritcular point in the circuit.Thanks Sue.
I really feel it is hard to get it right. How DC bias cancel AC signal? Could you explain a little more or give me a link to it?
Could you explain more about this?Without the inductor, the gate voltage is simply Vgs and the input signal can't affect it.
I've already explained it!Could you explain more about this?
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