4.For a coaxial transmission line shown in Fig. 2, the capacitance per unit length is
and the inductance per unit length is
. At high frequencies, the intemal inductance drops off (that is, approaching 0, and you should know which term is the internal inductance).
at high frquencies請務必將 internal inductance拿掉,並寫Zc之單位(即簡化
)。