Transmission Lines

Abstract

The transmission line consists of two or more parallel wires, which is used to transmit electrical energy from the generating station to the distribution system with a low frequency. Coaxial cables, parallel-wire transmission lines, and microstrip lines are used for power transmission. Using high insulation cable reduces electromagnetic interference during power transmission. The parallel-wire transmission line is used for overhead transmission and distribution networks, but the electromagnetic interference increases in this case. The microstrip line is used in the printed circuit board. The transmission line is also used in communication systems with high frequency and is also interconnected between neighboring networks to transfer electrical power under normal and emergency conditions. There are four parameters, namely, resistance, inductance, capacitance, and conductance in the transmission line. In the transmission line, the resistance is given as ohm per meter (ution system with a low frequencuctance is given as henrys per meter (H/m) or henrys per mile (H/mi), capacitance is in farad per meter (F/m), and conductance is in siemens per meter (S/m). The existence of these line parameters are found when the electric and magnetic fields are around the conductor. The transmission line conductors operate in transverse electromagnetic (TEM) mode, which means neither component of E nor H is in the direction of transmission. In this chapter, transmission line equation, velocity of wave propagation, wavelength, lossless propagation, distortionless transmission line, power, Smith chart, etc. is discussed.