coaxial cable and its types

Download Coaxial cable and its types

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introduction to Coaxial Cable ,Its Types,History

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  • 1. C o a x i a lC a b l e sName Adeel khurramRoll# 2kx3-O2Class BS-IT

2. History Of Coaxial Cable Coaxial cable was inventedby English engineer andmathematicianOliver Heaviside, whopatented the design in 1880. the discoveryis then fell into obscurity for many yearsbecause surely there was nothing to makepass in a coaxial cable !! The realdiscovery and its actual use dates back to1929 due to the need for a more efficient andwith less interferences conductor for thetransmissions of many telephone channels on a single "carrier". 3. IntroductIon to coaxIalcable Perhaps none of us have never thought that thedevelopment of radio communications would never havebeen possiblewithout the invention of coaxial cable,it is continuously used in ourapplications that we dont thinkabout that.Coaxial cable, orcoax is a type of that has aninner conductor surroundedby a tubular insulating layer, surrounded by a tubularconducting shield. Many coaxial cables also have aninsulating outer sheath or jacket. The term coaxial comesfrom the inner conductor and the outer shield sharing ageometric axis. 4. Structure Of Coaxial Cable Coaxial cable conducts electrical signal using an inner conductor (usually a Coaxial cable conducts electrical signal using an inner conductor (usually asolid copper, stranded copper or copper plated steel wire) surrounded by aninsulating layer and all enclosed by a shield, typically one to four layers ofwoven metallic braid andmetallic tape. The cable isprotected by an outer insulatingjacket.solid copper, stranded copper or copper plated steel wire) surrounded by aninsulating layer and all enclosed by a shield, typically one to four layers ofwoven metallic braid andmetallic tape. The cable isprotected by an outer insulatingjacket.Normally, the shield is keptat ground potential and avoltage is applied to the center conductor to carry electricalsignals. The advantage of coaxial design is that electric and magnetic fieldsare confined to the dielectric with little leakage outside the shield.Normally, the shield is keptat ground potential and avoltage is applied to the center conductor to carry electricalsignals. The advantage of coaxial design is that electric and magnetic fieldsare confined to the dielectric with little leakage outside the shield. 5. Uses of coaxial Cable Coaxial cable is used as a transmission line for radio frequencysignals. Its applications include feedlines connectingradio transmitters andreceivers with their antennas,computer network (Internet)connections, and distributingcable television signals.One advantage of coaxial overother types of radiotransmission line is that inan ideal coaxial cable theelectromagnetic field carrying thesignal exists only in the spacebetween the inner and outerconductors. Coaxial cable also provides protection of the signal fromexternal electromagnetic interference. 6. Connectors The ends of coaxial cables usually terminate withconnectors. Coaxial connectors are designed to maintaina coaxial form across the connection and have the sameimpedance as the attached cable.Connectors are usually platedwith high-conductivity metalssuch as silver ortarnish-resistant gold.Due to the skin effect, the RFsignal is only carried by the platingat higher frequencies and does not penetrate to theconnector body. Silver however tarnishes quickly and thesilver sulfide that is produced is poorly conductive,degrading connector performance, making silver a poorchoice for this application The ends of coaxial cables usually terminate withconnectors. Coaxial connectors are designed to maintaina coaxial form across the connection and have the sameimpedance as the attached cable.Connectors are usually platedwith high-conductivity metalssuch as silver ortarnish-resistant gold.Due to the skin effect, the RFsignal is only carried by the platingat higher frequencies and does not penetrate to theconnector body. Silver however tarnishes quickly and thesilver sulfide that is produced is poorly conductive,degrading connector performance, making silver a poorchoice for this application 7. SSiiggnnaall LLeeaakkaaggee Signal leakage is the passage of electromagnetic fields through theshield of a cable and occurs in both directions. Ingress is thepassage of an outside signal into the cable and can result in noiseand disruption of the desired signal.Egress is the passage of signal intended to remain within the cableinto the outside world and can result in a weaker signal at the end ofthe cableand radio frequency interference to nearby devices. Severe leakageusually results from improperly installed connectors or faults in thecable shield. 8. Types of Coaxial Cable Cat 3 UTP and STPCategory 3 UTP and STP (Cat 3) includeapplications as voice (telephony) or data (up to10 Mbps).More commonly Cat 3 is used on a networks forcable segments to workstations or printers. Cat3 isnot recommended for data installations since itsmaximum bandwidth of 10Mbps is rapidly beingexceeded by many LAN technologies. 9. TTyyppeess ((ccoonnttiinnuuee)) CCaatteeggoorryy 55 UUTTPP aanndd SSTTPPAApppplliiccaattiioonnss ffoorr CCaatteeggoorryy 55 UUTTPP aanndd SSTTPP iinncclluuddeevvooiiccee ((tteelleepphhoonnyy)) oorr ddaattaa ((uupp ttoo 110000 MMbbppss,, oorr wwiitthhcceerrttaaiinn tteecchhnnoollooggiieess,, 11000000 MMbbppss)).. CCaatt 55 iiss ssoommeettiimmeessuusseedd aass aa bbaacckkbboonnee;; hhoowweevveerr iiss rreessttrriicctteedd ttoo110000 mmeetteerrss iinn lleennggtthh.. IItt iiss ccuurrrreennttllyy tthhee mmoosstt ppooppuullaarrccaabblliinngg ffoorr ccoonnnneeccttiinngg wwoorrkkssttaattiioonnss aannddhhoorriizzoonnttaall ccaabbllee rruunnss dduuee ttoo iittss llooww ccoosstt,, hhiigghhbbaannddwwiiddtthh,, rreellaattiivvee eeaassee ooff iinnssttaallllaattiioonn,, aanndd eeaassee oofftteerrmmiinnaattiioonn wwiitthh RRJJ--4455 ccoonnnneeccttoorrss.. 10. Category of coaxial cables 11. Thanks