PI Network Impedance Matching |
Written by Bryce Ringwood |
This network is often used to match two resistive impedances Z1 and Z2 as shown below. They crop up in valve transmitter circuits and in antenna tuners. Q is a number representing the quality factor of a tuned circuit.
Data EntryAs with all these programs, data must be entered in SI units. It is up to you to enter the correct multiplier in all of the fields (p for pico, u for micro and so on.)
The example provided uses the same parameters that the impedance calculation uses in the article on impedance. Note that ${\displaystyle {{Z_2} \over{ Z_1}}({Q^2}+1) \gt 1}$ FormulaeThe following formulae were used:
$\displaystyle{{X_{C1}}={{Z_1} \over Q}}$ One can imagine the pain of trying to calculate these formulae on even a non-programmable calculator! The HP 65 didn't think quietly. While doing the calculations, the display would flash through all the intermediate results. The calculation would take maybe a second or two. I haven't attempted to program this on newer models of calculator. ReferenceHewlett Packard EE Pack for HP65 EE1-09A Hewlett Packard, 1974 |