Transmission Lines
Metallic Cable Transmission Media
Introduction
Transmission media
-It is included in the lowest layer of the OSI protocol hierarchy – the physical layer.
-Transmission medium is simply the path between a transmitter and a receiver in a communications system.
Guided Transmission media
-some form of conductor that provide conduit in which signals are contained -the conductor directs the signal examples: copper wire, optical fiber
Unguided Transmission media -wireless systems – without physical conductor -signals are radiated through air or vacuum -direction – depends on which direction the signal is emitted examples: air, free space
Cable transmission media
-guided transmission medium and can be any physical facility used to propagate EM signals between two locations
e.g.: metallic cables (open wire, twisted pair), optical cables (plastic, glass core)
Incident and Reflected wave
-Incident voltage is the voltage that propagates from sources towards the load
-Reflected wave is the voltage that propagates from the load towards the source. [pic]
Transmission line classifications
1) Balanced Transmission line - two wire balanced line. - both conductors carry current. But only one conductor carries signals.
[pic]
2) Unbalanced Transmission line - One wire is at ground potential and the other wire is at signal potential - advantage – only one wire for each signal - disadvantage – reduced immunity to noises [pic]
Baluns
Balanced transmission lines connected to unbalanced transmission lines e.g.: coaxial cable to be connected to antenna
Metallic Transmission Line Types 1)Parallel conductors 2)Coaxial cable
1)Parallel conductors consists of two or more metallic conductors(copper) separated by insulator–air,rubber etc. Most common -- Open Wire Twin lead Twisted Pair (UTP & STP)
Open Wire
- two-wire
Introduction
Transmission media
-It is included in the lowest layer of the OSI protocol hierarchy – the physical layer.
-Transmission medium is simply the path between a transmitter and a receiver in a communications system.
Guided Transmission media
-some form of conductor that provide conduit in which signals are contained -the conductor directs the signal examples: copper wire, optical fiber
Unguided Transmission media -wireless systems – without physical conductor -signals are radiated through air or vacuum -direction – depends on which direction the signal is emitted examples: air, free space
Cable transmission media
-guided transmission medium and can be any physical facility used to propagate EM signals between two locations
e.g.: metallic cables (open wire, twisted pair), optical cables (plastic, glass core)
Incident and Reflected wave
-Incident voltage is the voltage that propagates from sources towards the load
-Reflected wave is the voltage that propagates from the load towards the source. [pic]
Transmission line classifications
1) Balanced Transmission line - two wire balanced line. - both conductors carry current. But only one conductor carries signals.
[pic]
2) Unbalanced Transmission line - One wire is at ground potential and the other wire is at signal potential - advantage – only one wire for each signal - disadvantage – reduced immunity to noises [pic]
Baluns
Balanced transmission lines connected to unbalanced transmission lines e.g.: coaxial cable to be connected to antenna
Metallic Transmission Line Types 1)Parallel conductors 2)Coaxial cable
1)Parallel conductors consists of two or more metallic conductors(copper) separated by insulator–air,rubber etc. Most common -- Open Wire Twin lead Twisted Pair (UTP & STP)
Open Wire
- two-wire