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After seeing the design of a "24 MOSFET Digital Drive Transmitter" PCB mount on the K1KBW website, I decided to copy a 12 MOSFET version. Can anyone tell me how to calculate the output impedance matching circuit?

The reason why the gate driver EN pin in the PCB picture has no trace is that the IXDN614 gate driver is used instead of the IXDD614, because the IXDN614 has no EN pin, which can reduce unnecessary PCB traces and is cheaper.

I have never really calculated the output circuit impedance just copied what was on Steve QIX web site ....
However there are design tools there available..

http://www.classeradio.com/rfvalues.htm

This might help you.....


Wayne

(Vcc*Vcc) / (Pout+Pout)

Or, in englais


Voltage squared divided by twice the power out will need you pretty darn close to the real part of the impedance.

Device by device.   You then add the modules up and that will give you your final number.

--Shane
WP2ASS / ex KD6VXI

12 MOSFETs...

If you are going to run, say, 45V @ 12A (as an example), you could use something like 3.5uH to 4uH of inductance, and I would use a 1000pF vacuum variable as the series capacitor (although a sufficiently spaced air variable could work as well).  I would suggest at least 2000pF for the loading, and that may not be quite enough, but you can try it out.

Anyway, those are my suggestions.

Regards,  Steve

Thanks everyone for the help, the 12 FET amplifier will be a reality soon.

Here is some info:

https://norcalqrp.org/files/Class_E_Amplifiers.pdf

https://people.physics.anu.edu.au/~dxt103/class-e/ See references at the bottom for calculators.

https://people.physics.anu.edu.au/~dxt103/160m/class_E_amplifier_design.pdf Technical paper,

https://www.allaboutcircuits.com/technical-articles/load-network-response-and-design-equations-for-the-class-e-power-amplifier/

https://digital-library.theiet.org/doi/book/10.1049/sbew030e Book,

Спасибо !