Design RF transfomer

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Hello,

 

I have single turn magnetic loop and I want to make matched network for transferring power. The design need a impedance transformer to sending power. I am really pleased if users help me to design this transformer? for example if I find that ratio is 40/5 how can I determine those Toroidal Transformers primary turn? How can I find out my class AB power amplifier output impedance which should be matched to the transformer+magnetic loop? It is also noted that the frequency is 100KHz.

 

Thanks again

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The normal method for coupling/matching into a magnetic loop is to place a second loop inside the main loop.
The second loop is 20% the size of the main loop.
The main loop is tuned with a higher voltage variable capacitor.
The voltages produced around the loop are vey high as they are magnified by the Q of the loop.
This method provides the advantage of reducing the radiated harmonics as it is tuned and on receive it greatly reduces adjacent channel interference. The disadvantage is it requires retuning if you move more than 10khz.
The bandwidth can be increased by reducing the Q. I have seen this done by replacing a resistor across the loop.
To overcome the continuous rerunning requirements when changing frequency the variable capacitor is often remotely operated by a stepper motor, good AVR project!
There is another method of attaching a gamma match to the feed point.
Google it there are heaps of Info.
A transformer introduces more losses than this method.

I have made a few assumptions as you haven't informed what frequency and power are you using, are you transmitting, receiving or both? And are you changing frequency? I have assumed you are looking for a low or 50 ohm match?

Last Edited: Mon. Jun 17, 2019 - 11:08 PM
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On re reading your post I see you have included some of the info I was after.
Sorry have to go out for a while (women!)
Will get back soon.

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There are women in Australia? Who would have known!

Ross McKenzie ValuSoft Melbourne Australia

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valusoft wrote:

There are women in Australia? Who would have known!

 

The Group: 'Men at Work' even wrote a song about them too....

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Northeast Jim

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