Remarks regarding Transmission Lines

Author: Edmund A. Laport

The 19 different types of transmission lines for which formulas have been given in this section could be expanded to include many other practical and useful types that may have desirable characteristics for certain applications. A sufficient variety of types has been included to offer many ready-made designs as well as to suggest further varieties that may be developed according to need.

The unbalanced types shown represent means for obtaining characteristic impedances from roughly 50 ohms to some 500 ohms with open-wire constructions. They also include alternative configurations having special merits for economy and adaption to low-power transmission and to high-power transmission. The balanced lines discussed have characteristic impedances of the order of 125 to 650 ohms, using a maximum of six wires, and it is evident that lower values can be obtained if needed by employing configurations with a larger number of wires. The 19 configurations therefore cover a wide range of applications, some of which are conventional and common and others more specialized. Engineers should not hesitate to take advantage of special configurations of many sorts that may have particular merits for particular applications.