Tools & Calculators › Matching › Impedance Matching Calculator
Impedance Matching Calculator
Match a load to your rig with an L, Pi or Tee network. Every number has a source.
Every way to match it
Tap a card to load it into the workbench.
Schematic
Response
Parts
Sources & verification
L network: Hayward, Campbell & Larkin, Experimental Methods in RF Design (EMRFD), ARRL, 1st ed. (2003), p. 3.30, Eq 3.30–3.32 and Fig 3.65. Pi network: EMRFD p. 3.30, Eq 3.33–3.35 and Fig 3.66, with Q at the high-resistance side. Tee network: EMRFD p. 3.31, Eq 3.36–3.40 and Fig 3.67. Fig 3.67 is drawn here as corrected by the EMRFD errata (Sept 25, 2020; p. 3.31: the two capacitors are swapped in the printed figure). Every equation was checked against the page images, and the engine reproduces EMRFD’s own worked examples (10 Ω to 50 Ω at 7 MHz). Complex loads, Pi and Tee high-pass forms and the low-pass Tee use the same two-L-section method through a virtual resistance. SWR, bandwidths, harmonics and part stress come from a full circuit solve of ideal parts, with the terminations held at their f0 values; insertion loss uses coil Q from EMRFD p. 3.14, Table 3A. Coil turns come from the Toroid Turns data. Engine: .