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Title: Design of Impedance matching networks (howto) for transmitters. Post by: IN3IEX on October 03, 2011, 07:57:02 AM This is an useful tool from Berkeley: AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
http://bwrc.eecs.berkeley.edu/research/rf/projects/60ghz/matching/impmatch.html Only for CLC PI networks, if you wrote zero in the output tube (source) reactance field (because you don't know what it is), subtract the output tube anode capacitance from the input capacitance of the network you just computed in order to find the capacitance of the capacitor you should use there.. The frequency must be entered in Hz: for 3.8 MHz write 3800000 If you want to know how much of the Smith chart you can cover with your matching network at a given frequency just use this DOS software: http://www.science.unitn.it/~fontana/rfmatch.html Use Montecarlo simulation and define the nominal value and tolerance of the capacitors in order to obtain the maximum and minimum value of capacitance of your components. The inductor should have 0% tolerance. For instance 100 pF nominal and 80% tolerance will produce capacitances between 20 pF and 180 pF. Examples: http://www.ing.unitn.it/~fontana/antmatch.pdf Best Regards. Giorgio |