This module introduces and derives the telegrapher's equations, which describe how electrical signals behave as they move along transmission lines.
Let's look at just one little section of the line, and define
some voltages and currents
.
For the section of line
$\Delta (x)$ long, the voltage at its input is just
$V(x, t)$ and the voltage at the output is
$V(x+\Delta (x), t)$ . Likewise, we have a current
$I(x, t)$ entering the section, and another current
$I(x+\Delta (x), t)$ leaving the section of line. Note that both the voltage and the
current are functions of
time as well as
position.
Now when we let
$\Delta (x)\to 0$ , the left hand side again becomes a derivative, and on
the right hand side,
$V(x+\Delta (x), t)\to V(x, t)$ , so we have:
These are called the
telegrapher's equations and
they are all we really need to derive how electrical signalsbehave as they move along on transmission lines. Note what they
say. The first one says that at some point
$x$ along the line, the incremental
voltage drop that we experience as we move down the line is justthe distributed inductance
$L$ times the time derivative of
the current flowing in the line at that point. The secondequation simply tells us that the loss of current as we go down
the line is proportional to the distributed capacitance
$C$ times
the time rate of change of the voltage on the line. As youshould be easily aware, what we have here are a pair of
coupled linear differential equations in time and
position for
$V(x, t)$ and
$I(x, t)$
Questions & Answers
Do somebody tell me a best nano engineering book for beginners?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
In this morden time nanotechnology used in many field .
1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc
2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc
3- Atomobile -MEMS, Coating on car etc.
and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change .
maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.