# 7.1 Principle components

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Helps the user understand the various components in NFC and their mathematical significance. Very useful for discussions presented in the next module.

An NFC system consists of a passive network (the card/circuit with information) and an active circuit. We must also take into account the environment surrounding the device. A working knowledge of these three componenents is essential to understanding the inner mechanics of near field communication.

## The active circuit

The active circuit has a transmitting antenna that broadcasts RF waves and a number of electrodes that read values corresponding to how the environment reacts to the RF waves. All the processing power is centered in this active circuit and that is where the decoding will take place. This would be considered the reader in the traditional sense. In the following mathematical discussion, the electrode voltages of the active circuit will be values in a vector v1.

## The passive network

The passive network consists of a series of electrodes which are attached to impedances with values of infinity or zero (open/closed switches). This network might be located inside a phone or other device and is associated with the client side identification. The configuration of the passive network uniquely identifies the user, and thus, our problem becomes one of reverse engineering in which we try to determine the impedances. In our analysis, the passive network voltages are stored in the vector v1 and the impedances are represented by the matrix Y1. Since we are assuming no mutual impedances, this is a diagonal matrix. Rather than using infinity, we have represented the open switches with the very high impedance value of 10,000 ohms.

## The environment

The “evil channel” is our environment. It converts our beautiful binary impedances into ugly complex voltages. It is our job to understand its effects and make sure that our output is decipherable. The channel matrix we used was given to us and was measured experimentally. It can be modeled by a large square matrix which is of size N x N where N is the total number of voltages (in this case 41). The matrix is labeled Ys and is divided into 9 separate matrices, each representing the mutual interaction of different elements in our matrix.

For example, the elements in matrix W12 would reperesent how the electrodes with voltages v1 interact with the electrodes with voltages v2. Consequently, our answer lies in simplifying this matrix and trying to nullify it’s effect on the input (the Y1 matrix).

## Problem analysis

As previously stated, the relationship between input impedences and output voltages is non-linear by nature. Thus, our task will be to find some underlying patterns between input and output so that we may adequately decode the voltage values. When presented with a problem as open-ended as this, a number of techniques can be employed. We must make a preliminary analysis of the data through the use of well-constructed plots and principle component analysis.

Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
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.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
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