The voltage multiplication of your network is because of that the series circuit is inductive and the parallel resonant circuit is capacitive (LC L-match). Other option can be capacitive series circuit and inductive parallel circuit (CL L-match).
The loaded Q-factor almost equals the multiplication factor. So if you want a factor of 300, the loaded Q factor of the L and C in the LC L-match is 300. To have low loss, the Q factor of the components itself should be >>300.
When using LC circuits to make the inductive and capacitive behavior, the component Q factor must be even higher. If you want relative low loss, this is not the way to go as practical components will not have sufficient Q-factor.
You could do the transformation in steps. For example a cascade of two networks that do factor 17 each. I would go for a transfomer option. If it is a high voltage application, a two stage approach can be useful. First stage via transformer, the last stage via LC resonance.
The choice of circuit also depends on the source and the behavior of the load (can it be a short circuited load, or an open load, etc).
Estimate the Q factor of involved inductors and calculate equivalent inductor series resistances at the resonance frequency to repeat the simulation under realistic conditions.
Not at all. AC resistance will be considerably higher than DC resistance due to skin and proximity effects and there will be core losses in any inductor with magnetic core. Even an air core inductor has some additional eddy current losses.The resistance of the inductor is estimated to be 1 ohm. So, I estimated the Q of inductance should be 1000~1500. Does that sounds rational?
Not at all. AC resistance will be considerably higher than DC resistance due to skin and proximity effects and there will be core losses in any inductor with magnetic core. Even an air core inductor has some additional eddy current losses.
What's your inductor type?
In addition, you're assuming an ideal voltage source driving the circuit. Something that's rarely found in real electronics.
Your Q factor estimates seem very optimistic (you should measure Q at the operating frequency). Only physically very large coils will reach Q>1000. Miniature inductors have Q<100.
Also your capacitor Q estimate is too optimistic. You need an air dielectric capacitor to have Q > 5000.
For an LC L-network (L in series with source, C parallel to load):
Zload/Zin = rt(Vout/Vin). Qloaded = rt(Zload/Zin - 1 ), XL = Zin*Q, XC = Zload/Q.
an example:
you want a 1 to 20 voltage step and the load is 10 kOhms, all at 5 MHz. Because of conservation of energy, Zin = 10k/20^2 = 25 Ohms (and this is a real impedance).
So Qloaded = rt(10k/25 - 1) = 20.0, hence
XL = 25*20 = 500 -> L = 15.9 uH,
XC = 10k/20 = 500 -> C = 64.0 pF.
when the capacitor Q factor is 500, you lose 100%*20/500 = 4% in the capacitor.
Same formula is valid for the inductor.
The circuit is a low pass filter, with a very high peak (20 times) around the LC resonance frequency.
The two step approach uses two LC filters behind each other.
Your application is a mistery for me, but you may explore other schemes to get voltage multiplication factor of 300.
You can use an LC circuit in series with the source and an LC parallel resonant circuit parallel with the load to get a double peak response. If these frequencies are relatively close together, you need very high component Q, or you may need even three stages. In my opinion such an approach with three stages is close to technically impossible.
If you tell us something about power level, voltage level, the two frequencies and maximum physical size, we might be able to help you better.
Realistic Q numbers of cored inductors have been discussed in this previous thread. https://www.edaboard.com/threads/220098/
@toyonline: When using large air gaps (to get good temperature stability, high power, or low intermodulation), winding topology affects Q-factor. An example is copper in the fringe field zone of the air gap.
Regarding other solutions: frequencies, power, voltage, etc?
it is very hard to get Q higher than 100 unless you use good litz wire and low loss ferrites with suitable gaps, iron powder cores will give losses at moderate to high frequencies which will limit the real Q, run your flux density lower than 40mT peak in your ferrite also when you design your chokes, even better litz wire on air core toroids gives a practical method for high Q.
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