Application: The distortionless line. A coaxial line is made as shown in Figure 14.36. Material properties and dimensions are given in the figure. The design calls for a distortionless transmission line at 250 MHz.
(a) Assuming the outer radius must remain constant as given, what must be the radius of the inner conductor for the line to be distortionless? Assume copper conductors are thick.
(b) What are the characteristic impedance of the line and its attenuation constant for the design in (a)?
(c) If reduction of at most 10 dB in amplitude is allowed before an amplifier is required, calculate the distance between each two amplifiers on the line.