CHAPTER 12
METALLIC CABLE TRANSMISSION MEDIA
1)Provides a conduit in which electromagnetic signals are contained.
Guided Transmission Media
2)Emitted then radiated through air or a vacuum. Unguided Transmission Media
3)Used to propagate electromagnetic signals between two locations in a communications system. Cable Transmission Medium
4)Most common means of interconnecting devices in local area networks. Cable Transmission Systems
5)Metallic conductor system used to transfer electrical energy from one point to another using electrical current flow. Transmission line
6)Two basic kinds of waves. longitudinal and transverse
7)The rate at which the periodic wave repeats. Frequency
8)Currents that flow in opposite directions in a balanced wire pair. Metallic circuit currents
9)Currents that flow in the same direction. Longitudinal currents
10)Cancellation of common mode signals. Common mode rejection
11)One wire is at the ground potential, whereas the other is at signal potential. Single-ended or unbalanced
12)A circuit device used to connect a balanced transmission line to an unbalanced load. balun
14)Most common metallic cables used to interconnect data communications systems and computer networks. Parallel-conductor transmission lines and coaxial transmission lines.
15)Formed by twisting two insulated conductors around each other. Twisted-pair
16)Types of twisted pair. Unshielded twisted pair and Shielded twisted pair
17)Coupling that takes place when a transmitted signal is coupled into the received signal at the same end of the cable. Near-end crosstalk
18)Standard color code specified by the EIA for CAT-5 cable.
Pair 1: blue/white stripe and blue
Pair 2: orange/white stripe and orange
Pair 3: green/white strip[e and green
Pair 4: brown/white stripe and brown
19)Woven into a mesh. Braid
20)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. Plenum
21)Used for high data transmission rates to reduce losses and isolate transmission path.
Coaxial
22)Refers to the woven stranded mesh that surrounds some types of coaxial cables. Shielding
23)One layer of foil insulation and one layer of braided shielding. Dual shielded
24)Types of coaxial cables. Rigid air-filled; solid flexible
26)Uniformly distributed throughout the length of the line. Distributed parameters
27)Transmission characteristics of a transmission line. Secondary constants
28)Impedance seen looking into an infinitely long line. Surge impedance
29)Expressed the attenuation and the phase shift per unit length of a transmission line. Propagation constants
30)Ratio of the actual velocity of propagation of an electromagnetic wave through a given medium to the velocity of propagation through a vacuum. Velocity factor.
31)Relative permittivity of a material. Dielectric constant
32)Several ways in which signal power is lost.
Conductor loss, radiation loss, dielectric heating loss, coupling loss and corona
33)Voltage that propagates from the source toward the load. Incident voltage
34)Voltage that propagates that propagates from the load toward the source. Reflected voltage
35)Transmission line with no reflected power. Flat or non resonant line
36)Vector quantity that represents the ratio of reflected voltage to incident voltage or reflected current to incident current. Reflection coefficient
37)Incident power is absorbed by the load. Matched line
38)Incident power returned (reflected) to the source. Unmatched or mismatched line
39)Two travelling waves set up an interference pattern. Standing wave
40)Ratio of the maximum voltage to the minimum voltage or the maximum current to the minimum current of a standing wave on a transmission line. Standing-wave ratio
41)Used to matched transmission lines to purely resistive loads whose resistance is not equal to the characteristic impedance of the line. Quarter-wavelength transformers
42)A technique that can be used to locate an impairment in a metallic cable
Time domain reflectometry (TDR)
43)Return signal. Echo
44)Simply a flat conductor separated from a ground plane by an insulating di-electric material. Microstrip
45)Simply a flat conductor sandwiched between two ground planes. Stripline
0 comments:
Post a Comment