[MUSIC].
Today we have with us John Volakis. Today, he's going to be sharing with us
the basics of how radio frequency identification works.
All of you have probably seen bar codes on the back of packages that you may have
purchased. RFIDs, the acronym for Radio Frequency
Identification is the latest thing that has come.
And John is going to be sharing with us great ideas about how this can be applied
across consumer products, and in our cities.
>> RFID is a, an abbreviation. And means Radio Frequency Identification.
This presentation will provide you with an introduction as to what RFIDs are.
Why are they going to become so important to our lives?
And a little bit on how they work, and with that background, we will be able to
understand why they're so po, they will become so popular in the future.
What these RFIDs are? Well, they will be replacing the Barcodes
on our products. That is, today we go and we buy a shoe,
as indicated on the left-hand side here, of the slide.
But, in the, and it will have a Barcode. Or we buy a piece of gum and it will have
a Barcode. We buy a piece, a can, and it will have a
Barcode. In the future.
Instead of a bar code, we will replace it with an RFID tag which is shown to the
bottom left. This particular you know, tag will have
the product number. It will have the manufacturing date.
It will also say where was produced, what ports it was being enter the country.
What temperatures, perhaps, you went through.
But most importantly, it will also allow us to read this information without
looking at the product. And that's the big advantage of RFIDs.
That is, the information will be transmitted to a central location
wirelessly and we will be able to do inventory all the time, at any time.
And in the future you will be able to pack up your groceries or any items that
you will by from the store, or superstore.
You will go through a door that will have RFID, the readers, and your bill will be
sent to your house. And you would not even have to take out
your products at all. It would allow you to have information
about the product that you do not have right now.
Who made it, when it was made, any information about the history of the
product. How it was transported?
What temperatures it went through, if it was defrozen at any moment, and so on and
so forth. So that's for safety at the same time.
A key aspect of the RFID is a little chip which is on the right-hand side here in
red and an antenna that goes with it. The antenna is the largest piece of this
component that we call RFID. Let's proceed to talk about how it works.
There are a number of components that make the system work.
The two major components is the reader, which is a big structure shown to the, to
the left over here. And the reader has a big antenna and it
will be sitting somewhere. And the user will never know that it
exists. But it's much like when you walk through
the airports. You're being scanned, and this reader in
essence will scan the products. But all thousands of those products will
do it, and we'll see in a moment how this is being done.
Of course, this reader will be connected either with a wire, or wirelessly, to a
computer. The computer will contain all the
information about the products that is going to be collected by the reader.
And it will therefore be used for inventory purposes, or for collecting
information as to who bought what, and when, and so on.
We have the tag itself, this is the tag that will be on the product.
And every product will be assigned a specific tag that will have a number of
information which relates to the type of product you are able to buy.
We have the RFID tag component that is on that particular tag that you see here in
red. You have an antenna, as I mentioned,
which is the largest piece. You also have a very important aspect
which is the volitile, nonvolitile memory.
Nonvolitile memory means a memeory that can, that cannot be erased by anybody.
Because if you can erase the memory, then you can be able to change the type of
product. So you will not be allowed to change the
type of product. Unless you destroy the tag, of course, or
if you remove it. So it will be permanent.
There's also what's called an oscillator there, that you see.
And the oscillator is responsible for generating the frequency with which
you're going to speak, the reader is going to speak to the RFID.
This oscillator is nothing else but simply tuning the tagged communicator
certain frequency, just like your radios do.
So, in this particular case, it's around 900 megahertz.
And there will be a controller. a tag controller in a power management.
The controller tells the tag when to talk, when not to talk, so it manag-, and
the power management very, very important.
The reader will transmit a certain signal that will charge a capacitor which is on
the tag and then the tag will be able to use that energy to respond to it.
Let's now see a little bit more in detail how this technology works.
Where's the energies taken to communicate the reader and the tag?
We have the power, P sup T, P superscript T, which is the transmitter power, which
is sent by the reader. This is a signal, much like any antenna
sends a signal, just like your cellphone sends a signal, in this particular case a
900MHz signal will be sent to the tag. The signal will be coded, it will respond
because it will recognize a code or a key rather which is specific to that
particular tag or product. Then the Tag, if it does want to talk
back then you will send another signal back to the reader.
And the reader, that and that would generate a power and the reader will
receive that power in a back in to it, and you will have a certain code or keys
though. A major functionality of the tag, is
shown right to the bottom, you know, right of, of the slide.
While the signal is being transmitted back to the reader, there is a switch
inside the chip, possibly. And the switch changes, left and right,
and it changes the impedance, and as a result you will get sometimes a strong
signal, sometimes no signal. So sometimes you get a pulse back,
sometimes you get a weak pulse back. And that's the code.
So how fast it actually turns on and off the switch, and, and how many times it
does it, you will generate what we call a key.
And that key is exactly the code of the product.
So this is, all will be done through the code, and the code is generated by the
switching of the chip, which is already pre-programmed and you cannot change
that. That's why we call that as a non-volatile
in a memory, the Radar Cross-Section, or RCS, of the tag.
And that is what is being changed to a strong or weak pulse by using these
switchers. In addition you see the R which is the
distance between the reader and the tog. And if therefore you are very far away
from the tag, you will not be able to read it even if you're not in a direct
path. So you need to be close enough.
And that will depend also on how good your antenna is.
So there's a number of design characteristics that we must ensure in
order to be able to read the product from let's say 50 feet away or 100 feet away
or, you know perhaps even longer. What kind of deployment we're talking
about here? We're talking about putting tags
everywhere. Instead of a barcode, we will you know,
put it to track the products that go into your automobile.
The products that and the items that go into the assembly of your airplane.
Already your car keys have an RFID tag, so that when you go very, very close to
your car, the car will open. That's because it recognizes the fact
that you have the right key through the RFID tag which is embedded in the key.
In addition, you will have RFID tags on your IDs.
And therefore, as you walk by, the door will open for you because you have an
antenna and a chip on your ID that will identify who you are.
Pharmaceutical products will have a specific tag on them, instead of a bar
code telling when they were generated their history what they contain, and so
on and so forth. In my last technical slide, I will show
sort of a little miracle you may call it, of how the RFID tag and the reader
transmit and connect the information. It's a very interesting technology
because of the fact that it's very similar to people talking thousands of
languages. And then a reader will send a signal and
ask only one of the people or one of the products to speak their language and
everybody else will cease to talk when that happens.
First, on the top, in, or left here, the reader transmits a wake-up signal.
That signal, is like a key, it has a specific pulsation that you see over here
of zeroes and ones. And they come in a certain sequence.
When the tag receives that sequence, it will immediately respond to it.
Now, everybody will respond with their own language.
That is everybody will send a code back. The tag has their own code, but only one
of them will be selected at any one time to speak to the reader.
Once that selection is done, which will be done by the reader, the rest of the
tags will cease to talk. They will not be talking, so the product
information will be received. And then there will be another one, and
more than one. And all these things are happening of
course, in microseconds much like your cell phone.
When you push the button to talk somebody, one of the most complicated.
Things in the world are happening technologically, which is how you get
connected and how they find the other person on the side of the world.
Pretty much the same thing is happening with the tags.
Once the tag receives the wake-up call, it will generate a 0 random number.
We will call that key number one, and the key number one will be sent to the
reader. The reader will respond by transmitting
back the same key number one, and that's sort of saying hey, I've got your key I
begin, I'm understanding you. So this kind of, what we call that a
handshake. The tag will receive the handshake, which
is key number 1. And it receives its own key back from the
reader, that means that it's been acknowledged, and only one will be
acknowledged at any one time. Then the tag will send it's code, it's
electronic product code, which is the bar code if you want to call it that way.
It will send another digital signal back, much like the one that we show on the top
here. And the electronic product code will be
received by the reader. The reader, then, will send back a, the
key number one, a valid key number 1, which generates another 16 bit random
number called key two. And then the key 2 gets back to the
reader again, and then key 2 is being transmitted and the tag executes, another
tag rather, is being excited. And then we'll go to key 3, key 4, and so
on and so forth until all of the tags have been read.
And this is happening within a few you know, seconds of course.
there's a number of challenges. One of the biggest problems is the size
of every one of these tags. That is they have to go into the tiniest
little product. They're already being used into the
larger product. In addition, the cost associated with
them. They have to be down to a cent or a
fraction of a cent. That's a very major challenge as well.
These two challenges create a design requirement for us engineers.
One of them is designing the antenna to be very small, but at the same time to
have very good efficiency and to be able to work even when it's embedded, for
example, in a tire. And a rubber tire is very lossy and it
it's not a good medium of transmitting the our signal.
So therefore you must still nevertheless find ways how to transmit the signal
through these kinds of products. In addition, it must work when you put
the tag on water, on a waterly subject, jelly subject, on metal.
On different kinds of like I said rubber, behind you know, other products, when
it's embedded within the aircraft in, in either an engine and so on.
There's, there's challenges that it will be ubiquitous as to where it works and
where it's going to be placed and we don't know where.
So therefore the product you know, has to have all these flexibilities some
references here.