Transmission Line Made from Twisted Pair Wire

[file: twist.mcd]

Formulas included in this spreadsheet:

• Twisted-pair characteristic impedance ZTWIST()

• Twisted-pair propagation delay PTWIST()

• Twisted-pair inductance LTWIST()

• Twisted-pair capacitance CTWIST()

Variables used:

• d Diameter of wire (in.)

• s Separation between wires (in.)

• x Length of wire (in.)

• er Effective relative dielectric constant of medium between wires

Characteristic impedance of twisted pair (W):

Propagation delay per in. twisted pair (s/in.):

Inductance of twisted pair (H):

Capacitance of twisted pair (F):

         


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Example twisted-pair calculations

Diameter of AWG 24 wire (in.)             

Length of wire (in.)                             

Separation between wire centers (in.)   

Relative dielectric constant                  

Characteristic impedance (W):

Total inductance (H):

Same result in nH:

Inductance per in. (H):

Total capacitance (F):

Same result in pF:

Capacitance per in. (F):

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