# A report onCoaxial cable and Transmission line

Coaxial cable is a type of transmission line, used to carry high-frequency electrical signals with low losses.

- Coaxial cable

Types of transmission line include parallel line (ladder line, twisted pair), coaxial cable, and planar transmission lines such as stripline and microstrip.

- Transmission line

## Feed line

In a radio antenna, the feed line (feedline), or feeder, is the cable or other transmission line that connects the antenna with the radio transmitter or receiver.

The most widely used types of feed line are coaxial cable, twin-lead, ladder line, and at microwave frequencies, waveguide.

Antenna or aerial is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver.

Antenna or aerial is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver.

An antenna lead-in is the transmission line, or feed line, which connects the antenna to a transmitter or receiver.

Such a structure is normally connected to the return connection of an unbalanced transmission line such as the shield of a coaxial cable.

## Telegrapher's equations

The telegrapher's equations (or just telegraph equations) are a pair of coupled, linear partial differential equations that describe the voltage and current on an electrical transmission line with distance and time.

In long distance rigid coaxial cable, to get very low dielectric losses, the solid dielectric may be replaced by air with plastic spacers at intervals to keep the center conductor on axis.

## Oliver Heaviside

English self-taught mathematician and physicist who brought complex numbers to circuit analysis, invented a new technique for solving differential equations (equivalent to the Laplace transform), independently developed vector calculus, and rewrote Maxwell's equations in the form commonly used today.

English self-taught mathematician and physicist who brought complex numbers to circuit analysis, invented a new technique for solving differential equations (equivalent to the Laplace transform), independently developed vector calculus, and rewrote Maxwell's equations in the form commonly used today.

Undertaking research from home, he helped develop transmission line theory (also known as the "telegrapher's equations").

That same year he patented, in England, the coaxial cable.

Two-conductor flat cable used as a balanced transmission line to carry radio frequency signals.

Two-conductor flat cable used as a balanced transmission line to carry radio frequency signals.

It can have significantly lower signal loss than miniature flexible coaxial cable, the main alternative type of feedline at these frequencies; for example, type RG-58 coaxial cable loses 6.6 dB per 100 m at 30 MHz, while 300 ohm twin-lead loses only 0.55 dB.

Twin-lead is also used in amateur radio stations as a transmission line for balanced transmission of radio frequency signals.

## Characteristic impedance

The characteristic impedance or surge impedance (usually written Z0) of a uniform transmission line is the ratio of the amplitudes of voltage and current of a single wave propagating along the line; that is, a wave travelling in one direction in the absence of reflections in the other direction.

The characteristic impedance of coaxial cables (coax) is commonly chosen to be 50 Ω for RF and microwave applications.