## Coax Impedance Calculator

Calculate the impedance of a coaxial transmission line.
D (mm) Er |
d (mm) |
Impedance |

Notes:

*Optimal D/d ratio for breakdown voltage is 2.718.

*Optimal D/d ratio for power transfer is 1.65.

*Optimal D/d ratio for minimum attenuation is 3.59.

*Equation from Brian C. Wadell, “Transmission Line Design Handbook”