Field and Wave Electromagnetics 2nd Edition by David Cheng

Exercise 62

It is desired to construct uniform transmission lines using polyethylene ( r = 2.25) as the dielectric medium. Assuming negligible losses, (a) find the distance of separation for a 300-( ) two-wire line, where the radius of the conducting wires is 0.6 (mm); and (b) find the inner radius of the outer conductor for a 75-( ) coaxial line, where the radius of the center conductor is 0.6 (mm).