## The VK1SV class-e calculator

This is an aid for designing class-e amplifiers, as described in Nathan Sokal's paper titled "Class-E RF power amplifiers", published in QEX Jan/Feb 2001. You need to provide Q, Vcc, Vo, P, F and L1 and the calculator will provide values for the rest. See the schematic below for details.

This page is a modified version of the original here to allow input of SI suffixed units and produce them on output as well as calculate L1min, and fr1/fr2.

Enter Q (around 5 is a good start):
Enter Vcc: V
Enter Vo (transistor/FET saturation voltage): V
Enter Coss (transistor/FET output capacitance): F
Enter frequency: Hz
Enter the desired power output: W
Enter L1: H

R is: Ω (Impedance transformer to 50Ω: secondary (50Ω) to primary (amplifier) turns ratio: )
C1 is: F (XC1 is: Ω)
C2 is: F (XC2 is: Ω)
L1min is: Ω (XL1 is: Ω)
L2 is: H (XL2 is: Ω)
XL2 - XC2 = Ω
Expect Icc of at least: I
Select a FET/transistor with a max Vds/Vce of at least: V (Includes a safety factor of 0.8)
1 / fr1 = Hz. When Q1 closed, should be less than the frequency of operation.
1 / fr2 = Hz. When Q1 open, should be greater than the frequency of operation.
1 / (fr1 + f2 half period) = Hz. Should be about equal to the frequency of operation.

Schematic from Nathan Sokal's paper titled "Class-E RF power amplifiers", published in QEX Jan/Feb 2001.

For more info on designing Class-E amplifiers for LF/MF, see VK1SV's Class-E for beginners

L1min and Fr1/2 calculations are from here.

Many thanks to Daniel O'Connor (doconnor AT gsoft.com.au) for his contribution of the SI prefix capability, the L1min and Fr1/2 calculation as well as a general tidy up of the javascript code!

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