Relating to the frequency in the circuit, I have to do an AC analysis. But
I understand, that I have to use the .TRAN to simulate the oscillation.
Why do you say you have to do an AC analysis?
An AC analysis tells you nothing about what the oscillator is doing. It
won't tell you the frequency where it oscillates. It won't tell you even
IF it is oscillating. You MUST use a .TRANsient analysis to check for (a)
whether it oscillates, and (b) at what frequency.
The antenna load doesn't do anything.
...
I thought it was right to simulate it with a single resistor, because the
only thing I knew about antennas was that they are oscillating circuit. So
I removed the imaginary content and only the resistor was left. I will
improve it as you told me.
That's correct to use the resistor. At the antenna's resonant frequency,
the antenna looks like a resistor, to ground. (A quarter-wave antenna over
a ground plane probably looks like about 35 ohms, BTW.)
However, a resistor with the other end floating, or shorted across the
resistor, is just an open circuit (i.e., no load) because zero current
flows to it.
It looks like your power supply voltage, V1, is not set to any DC voltage.
Its AC value should be 0. Its DC value should be 6.
I know it, because the schematic told me it is a DC voltage. But I had to
change it due to the AC analysis for the frequency.
This doesn't make sense. What you have is a 0V power supply with about 6V
of AC ripple. I can't figure out why you would want to do that, nor what
you would get from your AC analysis. Effectively, your AC analysis shows
you how much the AC ripple on the power supply feeds through to the output.
Also, with 0V DC applied, the transistors are non-functional.
I can't emphasize enough that you really need to be doing a TRANsient
analysis. I think you don't understand yet the purpose of an AC analysis.
Regards,
Andy
