Transmission lines guide electrical energy from one point to another. They have two ends - an input end connected to the source, and an output end connected to the load. Common types of transmission lines include twisted pair, coaxial cable, and optical fiber. Twisted pair comes in unshielded and shielded variants, with shielded providing better protection against interference. Coaxial cable carries signals of higher frequencies than twisted pair. Optical fiber uses light pulses to transmit data over long distances at high speeds. Wireless transmission uses electromagnetic waves like radio waves, microwaves, and infrared to transmit data through the air without a physical medium.

1. TRANSMISSION LINE

3. Classes of transmission media

5. ELECTROMAGNETIC SPECTRUM

18. Shielded Twisted Pair

25. Categories of Coaxial cable

29. Fiber construction

30. Fiber-optic cable connectors

31. ST connector TOS Link connector

33. Optical fiber

34. Bending of light ray

35. Propagation modes

36. Modes of Propagation

40. Fiber types

42. UNGUIDED MEDIA: WIRELESS

43. Propagation methods

44. Bands

46. Omnidirectional antenna

48. Unidirectional antennas