(CHAPTER 12) METALLIC CABLE TRANSMISSION MEDIA (78-81).pdf

BOOK REVIEW IN COMMUNICATIONS Electronic Communications System By Wayne Tomasi CHAPTER 12 METALLIC CABLE TRANSMISSION MEDIA # DEFINITIONS TERMS Provides a conduit in which elect...

BOOK REVIEW IN COMMUNICATIONS Electronic Communications System By Wayne Tomasi CHAPTER 12 METALLIC CABLE TRANSMISSION MEDIA # DEFINITIONS TERMS Provides a conduit in which electromagnetic signals Guided Transmission 1) are contained. Media Unguided Transmission 2) Emitted then radiated through air or a vacuum. Media Used to propagate electromagnetic signals between Cable Transmission 3) two locations in a communications system. Medium Most common means of interconnecting devices in Cable Transmission 4) local area networks. Systems Metallic conductor system used to transfer electrical 5) energy from one point to another using electrical Transmission line current flow. longitudinal and 6) Two basic kinds of waves. transverse 7) The rate at which the periodic wave repeats. Frequency Currents that flow in opposite directions in a 8) Metallic circuit currents balanced wire pair. 9) Currents that flow in the same direction. Longitudinal currents 10) Cancellation of common mode signals. Common mode rejection One wire is at the ground potential, whereas the Single-ended or 11) other is at signal potential. unbalanced A circuit device used to connect a balanced 12) transmission line to an unbalanced load. balun Prepared By : MA. ELAINE L. CORTEZ 78 BOOK REVIEW IN COMMUNICATIONS Electronic Communications System By Wayne Tomasi Most common metallic cables used to interconnect Parallel-conductor 14) data communications systems and computer transmission lines and networks. coaxial transmission lines. Formed by twisting two insulated conductors around 15) Twisted-pair each other. Unshielded twisted pair 16) Types of twisted pair. and Shielded twisted pair Coupling that takes place when a transmitted signal 17) is coupled into the received signal at the same end Near-end crosstalk of the cable. Pair 1: blue/white stripe and blue Pair 2: orange/white Standard color code specified by the EIA for CAT-5 stripe and orange 18) cable. Pair 3: green/white strip[e and green Pair 4: brown/white stripe and brown 19) Woven into a mesh. Braid Name given to the area between the ceiling and the root in a single-story building or between the ceiling 20) Plenum and the floor of the next higher level in a multi-story building. Used for high data transmission rates to reduce losses 21) Coaxial and isolate transmission path. Refers to the woven stranded mesh that surrounds 22) Shielding some types of coaxial cables. One layer of foil insulation and one layer of braided 23) shielding. Dual shielded Prepared By : MA. ELAINE L. CORTEZ 79 BOOK REVIEW IN COMMUNICATIONS Electronic Communications System By Wayne Tomasi Rigid air-filled; solid 24) Types of coaxial cables. 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 Expressed the attenuation and the phase shift per 29) Propagation constants unit length of a transmission line. Ratio of the actual velocity of propagation of an 30) electromagnetic wave through a given medium to Velocity factor. the velocity of propagation through a vacuum. 31) Relative permittivity of a material. Dielectric constant Conductor loss, radiation loss, dielectric heating 32) Several ways in which signal power is lost. loss, coupling loss and corona Voltage that propagates from the source toward the 33) Incident voltage load. Voltage that propagates that propagates from the 34) Reflected voltage load toward the source. 35) Transmission line with no reflected power. Flat or non resonant line Vector quantity that represents the ratio of reflected 36) voltage to incident voltage or reflected current to Reflection coefficient incident current. 37) Incident power is absorbed by the load. Matched line Prepared By : MA. ELAINE L. CORTEZ 80 BOOK REVIEW IN COMMUNICATIONS Electronic Communications System By Wayne Tomasi Unmatched or 38) Incident power returned (reflected) to the source. mismatched line 39) Two travelling waves set up an interference pattern. Standing wave Ratio of the maximum voltage to the minimum 40) voltage or the maximum current to the minimum Standing-wave ratio current of a standing wave on a transmission line. Used to matched transmission lines to purely resistive Quarter-wavelength 41) loads whose resistance is not equal to the transformers characteristic impedance of the line. A technique that can be used to locate an Time domain 42) impairment in a metallic cable reflectometry (TDR) 43) Return signal. Echo Simply a flat conductor separated from a ground 44) Microstrip plane by an insulating di-electric material. Simply a flat conductor sandwiched between two 45) Stripline ground planes. Prepared By : MA. ELAINE L. CORTEZ 81