Coaxial Cable Field Theory

[Transmission Line Parameters of a Coaxial Cable]

Electric and magnetic fields:

: radii of inner and outer conductors

Power carried by the cable:

: peak incident voltage between inner and outer conductors

: peak incident total current on inner or outer conductor

: average incident power transmitted through the coaxial cable

Characteristic impedance:

Propagation constant:

Transmission line parameters:

Velocity factor:

Dielectric constant:

[Higher-order modes]

Mode order with increasing cutoff frequency:

TEM, TE11, TE21, TE31, TM01, TM11, TM21

TM01:

TM11:

TM21:

TE11:

TE21:

TE31:

TM modes:

c = a/b = 3

TE mode:

TEm1 mode:

TEmn mode:

c = a/b = 3

Design: 5.41GHz, =55.45mm

f_c = 5.41 × 0.95 = 5.14GHz, λ = 58.4mm

TE₁₁: a = 14.3, d = 28.7

TE₂₁ cutoff: λ = 30.6, f = 9.8GHz