Transmission line

QuestionsCategory: Wave and OpticsTransmission line
Profile photo of HarishchandraHarishchandra asked 4 years ago
Profile photo of Big Bang BoffinBig Bang Boffin Moderator replied 4 years ago

Nice question. I don’t know it at the moment. It does seem interesting. I will do some research and try to answer unless someone already does.

1 Answers
Best Answer
Profile photo of Big Bang BoffinBig Bang Boffin Moderator answered 3 years ago

 A transmission line is a specially designed cable, to transmit alternating current signals of very high frequency(Radio Frequency)
NEED:
Electrical Signals with low frequencies like the ones used in our households(50-100Hz) can be transmitted through the usual copper wires without any significant power losses. However, at high frequencies the losses become significant. They cannot be used to carry currents in the radio frequency range, above about 30 kHz, because the energy tends to radiate off the cable as radio waves, causing power losses. Radio frequency currents also tend to reflect from discontinuities in the cable such as connectors and joints, and travel back down the cable toward the source.These reflections act as bottlenecks, preventing the signal power from reaching the destination.
Ref:http://farside.ph.utexas.edu/teaching/em/lectures/node86.html
DISTINGUISHING FEATURE:
 Transmission lines use specialized construction, and impedance matching, to carry electromagnetic signals with minimal reflections and power losses. The distinguishing feature of most transmission lines is that they have uniform cross sectional dimensions along their length, giving them a uniform impedance, called the characteristic impedance, to prevent reflections.
COMMON TYPES
 Parallel Wire, Microstrip line and Coaxial Cables.