This is the summary notes of the important terms and concepts in Chapter 12 of the book "Electronic Communications System" by Wayne Tomasi. The notes are properly synchronized and concise for much better understanding of the book. Make sure to familiarize this review notes to increase the chance of passing the ECE Board Exam.
Provides a conduit in which electromagnetic signals are
Guided Transmission Media
Emitted then radiated through air or a vacuum.
Unguided Transmission Media
Used to propagate electromagnetic signals between two
locations in a communications system.
Cable Transmission Medium
Most common means of interconnecting devices in local area
Cable Transmission Systems
Metallic conductor system used to transfer electrical energy
from one point to another using electrical current flow.
Two basic kinds of waves.
longitudinal and transverse
The rate at which the periodic wave repeats.
Currents that flow in opposite directions in a balanced wire
Metallic circuit currents
Currents that flow in the same direction.
Cancellation of common mode signals.
Common mode rejection
One wire is at the ground potential, whereas the other is at
Single-ended or unbalanced
A circuit device used to connect a balanced transmission line
to an unbalanced load.
Most common metallic cables used to interconnect data
communications systems and computer networks.
Parallel-conductor transmission lines and
coaxial transmission lines.
Formed by twisting two insulated conductors around each other.
Types of twisted pair.
Unshielded twisted pair and Shielded
Coupling that takes place when a transmitted signal is coupled
into the received signal at the same end of the cable.
Standard color code specified by the EIA for CAT-5 cable.
Pair 1: blue/white stripe
Pair 2: orange/white
stripe and orange
Pair 3: green/white stripe
Pair 4: brown/white stripe
Woven into a mesh.
Name given to the area between the ceiling and the root in a
single-story building or between the ceiling and the floor of the next higher
level in a multi-story building.
Used for high data transmission rates to reduce losses and
isolate transmission path.
Refers to the woven stranded mesh that surrounds some types of
One layer of foil insulation and one layer of braided
Types of coaxial cables.
Rigid air-filled; solid flexible
Uniformly distributed throughout the length of the line.
Transmission characteristics of a transmission line.
Impedance seen looking into an infinitely long line.
Expressed the attenuation and the phase shift per unit length
of a transmission line.
Ratio of the actual velocity of propagation of an
electromagnetic wave through a given medium to the velocity of propagation
through a vacuum.
Relative permittivity of a material.
Several ways in which signal power is lost.
Conductor loss, radiation loss, dielectric
heating loss, coupling loss and corona
Voltage that propagates from the source toward the load.
Voltage that propagates that propagates from the load toward
Transmission line with no reflected power.
Incident power returned (reflected) to the source.
Unmatched or mismatched line
Two travelling waves set up an interference pattern.
Ratio of the maximum voltage to the minimum voltage or the
maximum current to the minimum current of a standing wave on a transmission
Used to match transmission lines to purely resistive loads
whose resistance is not equal to the characteristic impedance of the line.
A technique that can be used to locate an impairment in a
Time domain reflectometry (TDR)
Simply a flat conductor separated from a ground plane by an
insulating di-electric material.
Simply a flat conductor sandwiched between two ground planes.