1. C o a x i a l
C a b l e s
Name Adeel khurram
Roll# 2kx3-O2
Class BS-IT
2. History Of Coaxial Cable
• Coaxial cable was invented
by English engineer and
mathematician
Oliver Heaviside, who
patented the design in 1880. the discovery
is then fell into obscurity for many years
because surely there was nothing to make
pass in a coaxial cable !! The real
discovery and its actual use dates back to
1929 due to the need for a more efficient and
with less interferences conductor for the
transmissions of many telephone channels on a single "carrier".
3. IntroductIon to coaxIal
cable
• Perhaps none of us have never thought that the
development of radio communications would never have
been possible
without the invention of coaxial cable,
it is continuously used in our
applications that we don’t think
about that.Coaxial cable, or
coax is a type of that has an
inner conductor surrounded
by a tubular insulating layer, surrounded by a tubular
conducting shield. Many coaxial cables also have an
insulating outer sheath or jacket. The term coaxial comes
from the inner conductor and the outer shield sharing a
geometric 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 a
solid copper, stranded copper or copper plated steel wire) surrounded by an
insulating layer and all enclosed by a shield, typically one to four layers of
woven metallic braid and
metallic tape. The cable is
protected by an outer insulating
jacket.
solid copper, stranded copper or copper plated steel wire) surrounded by an
insulating layer and all enclosed by a shield, typically one to four layers of
woven metallic braid and
metallic tape. The cable is
protected by an outer insulating
jacket.
Normally, the shield is kept
at ground potential and a
voltage is applied to the center conductor to carry electrical
signals. The advantage of coaxial design is that electric and magnetic fields
are confined to the dielectric with little leakage outside the shield.
Normally, the shield is kept
at ground potential and a
voltage is applied to the center conductor to carry electrical
signals. The advantage of coaxial design is that electric and magnetic fields
are 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 frequency
signals. Its applications include feedlines connecting
radio transmitters and
receivers with their antennas,
computer network (Internet)
connections, and distributing
cable television signals.
One advantage of coaxial over
other types of radio
transmission line is that in
an ideal coaxial cable the
electromagnetic field carrying the
signal exists only in the space
between the inner and outer
conductors. Coaxial cable also provides protection of the signal from
external electromagnetic interference.
6. Connectors
• The ends of coaxial cables usually terminate with
connectors. Coaxial connectors are designed to maintain
a coaxial form across the connection and have the same
impedance as the attached cable.
Connectors are usually plated
with high-conductivity metals
such as silver or
tarnish-resistant gold.
Due to the skin effect, the RF
signal is only carried by the plating
at higher frequencies and does not penetrate to the
connector body. Silver however tarnishes quickly and the
silver sulfide that is produced is poorly conductive,
degrading connector performance, making silver a poor
choice for this application
• The ends of coaxial cables usually terminate with
connectors. Coaxial connectors are designed to maintain
a coaxial form across the connection and have the same
impedance as the attached cable.
Connectors are usually plated
with high-conductivity metals
such as silver or
tarnish-resistant gold.
Due to the skin effect, the RF
signal is only carried by the plating
at higher frequencies and does not penetrate to the
connector body. Silver however tarnishes quickly and the
silver sulfide that is produced is poorly conductive,
degrading connector performance, making silver a poor
choice for this application
7. SSiiggnnaall LLeeaakkaaggee
• Signal leakage is the passage of electromagnetic fields through the
shield of a cable and occurs in both directions. Ingress is the
passage of an outside signal into the cable and can result in noise
and disruption of the desired signal.
Egress is the passage of signal intended to remain within the cable
into the outside world and can result in a weaker signal at the end of
the cable
and radio frequency interference to nearby devices. Severe leakage
usually results from improperly installed connectors or faults in the
cable shield.
8. Types of Coaxial Cable
• Cat 3 UTP and STP
Category 3 UTP and STP (Cat 3) include
applications as voice (telephony) or data (up to
10 Mbps).
More commonly Cat 3 is used on a networks for
cable segments to workstations or printers. Cat
3 is
not recommended for data installations since its
maximum bandwidth of 10Mbps is rapidly being
exceeded by many LAN technologies.