
72 Microwave Engineering
Electric eld intensity:
E
V
b a
=
ρ ln( )/
(2.98a)
Magnetic eld intensity:
H
I
=
2πρ
(2.98b)
Velocity of propagation for voltage and current waves:
υ
µ ε
=
0
r r
(2.99a)
Wavelength in coaxial cable:
λ
µ ε
=
0
r r
(2.99b)
High frequency inductance per unit length:
L b a
r
=
π
0
2
ln( )/
(2.99c)
High frequency capacitance per unit length:
C
b a
r
=
2
0
ln( )/
(2.99d)
Characteristic impedance:
Z
L
C
b
a
0
1
2
= =
π
µ
ε
ln
(2.99e)
Maximum allowable rms voltage:
V
aE b a
b a
d
max
ln( )
( )
=
2
/
/
(2.99f)
where E
d
is the dielectric strength of the insulating material lled between
the inner and outer conductors. All other parameters involved in the above
equations were ...