Wireless Data Transmission

Added: 2026-05-05

[00:00:00]Hey, thanks for joining me again. This video is about wireless data transmission. We're getting into the physics about what is going on in the process of sending information from one thing to another. This could be considered for like oldtimey radio all the way up to modern day with smartphone technology. When we're trying to send information, whether it's data or music or a podcast, what exactly is going on?

[00:00:20]We're going to touch upon the physics, what is happening at the fundamental level and what is the underlying science behind broadcasting as well as receiving data. All right. Now before we get into the details about what a broadcast and what a reception of a signal looks like we have to remember the electromagnetic spectrum because spoiler when we're sending data we are using the electromagnetic spectrum we are using light. Remember electromagnetic spectrum is another word for light. All right now we are mostly talking about at least in terms of like human technology this side of the spectrum when we send information wirelessly we are doing that almost exclusively with either radio waves microwaves or a little bit of infrared.

[00:00:55]Radio and microwaves are the predominant method of sending information. There are strengths with those couple of types that we're not really going to get into uh right here. Okay. Now, what we need to remember about electromagnetic radiation is what is oscillating? And what do I mean by that? EM or light, these are waves. And we know that all waves regardless of type, they all transfer energy through vibrations or through oscillations. Or in fact, vibrations and oscillations are are kind of synonymous here. Let's see a couple or remember a couple of examples. Ocean waves, those are oscillating water molecules. the water, the ocean particles so to speak are moving either up and down or left and right or maybe kind of a combination of both. We learned already that sound waves those are the vibrations or the oscillations of air particles. These are both examples of waves and either example maybe we can imagine the wave is moving to the right and we see the particles whether it's water or air they are vibrating in a certain way either kind of up down left right or like left right over here. Uh but that's what all waves are. When we talked about light waves, electromagnetic waves, remember electromagnetic waves, the thing that is oscillating, the thing that's vibrating, it's a little weird. It is electric and magnetic fields. Okay? Ocean waves are are very easy to visualize because obviously you can think of an ocean wave. You could feel an ocean wave with your with your hands. Sound waves are a little less intuitive because you don't see the individual air particles, but like if you took your hand and you waved your hand back and forth, maybe like you you can feel the breeze. So you can kind of tell or prove to yourself that there is in fact air present. But man, electric and magnetic fields, we don't see them kind of stationary or in a in a usual kind of way. So it's unintuitive this definition right here. But ne nevertheless, it's important that we remember that light waves are electric and magnetic fields that are vibrating back and forth that are oscillating back and forth. This was a visual I showed in a prior video. In fact, a light wave is two waves. It's this combination of electricity and magnetism. I gave an analogy in a prior video how we are kind of surrounded by an ocean of light. Now, we don't feel many types of light. We don't hear types of light, but we do see some types. So, right now, there are giant radio waves passing you all the time. We don't really detect those as humans. We do detect a narrow band of electromagnetic waves with our eyes.

[00:02:58]When certain size waves enter our eyes, we might see red or blue or green or colors in between. Okay? But nevertheless, again, light is these oscillating electric and magnetic fields. Also everybody, it's worth reminding ourselves because it's going to play a role here that we learned about this connection for electricity and magnetism way back when we were learning about how like electric generators work, how electric motors work, how wireless chargers work. We also saw these bullet point effects when we were learning how a speaker and how a microphone work. Okay, there is this connection between electricity and magnetism. All right. Well, everybody, the big reminder that we need using these bullet points right here is that electric and magnetic fields, they kind of create each other. or or said a better way, you don't really have one without the other. If you're in my own class, I may have used this analogy before. Electricity and magnetism or electric and magnetic fields. They're really not separate entities. They are like two sides of the same coin. You can have a coin and you could look at one side electricity or the other side magnetism, but but really they go hand in hand. You can't really separate them.

[00:03:58]If you have an electric field, you also have a magnetic field. That is an important detail for us to remember.

[00:04:03]Getting into how we broadcast information. Well, here is that diagram again. Electricity and magnetism. It's kind of modeling this idea. Notice you don't just have an electric wave, you have an electric and magnetic field.

[00:04:14]These two waves are perpendicular. The two sides of the coin. There's one thing on the other side. Okay. So now with those reminders under our belt, let's get into this idea of broadcasting information. Everybody, when we are sending information, we are using light waves. We are using whether it's radio or microwave or maybe infrared. We are using electromagnetic waves. We're using waves of light. So if we remember that electromagnetic waves are in fact these oscillating magnetic and electric fields, how do we create an electromagnetic wave in order to send a signal? Well, we need to create either an electric or a magnetic field. What I say right here is if we're able to make a magnetic field, well, everybody, two sides of the same coin. Making a magnetic field automatically creates both. An electromagnetic field. If we create an electromagnetic field, that that is us creating light, everybody.

[00:05:02]So, let's go back to our four bullet points. How could I create a magnetic field? What is a way that we could make a magnetic field? Can you identify it, everybody? It was this bullet point right here from this list we learned if you're in my own physics class months ago. If I move an electron, if I can wiggle an electron, say, back and forth, that makes a magnetic field. I will make, in fact, a magnetic field wiggling back and forth. And bam, I can't have one without the other. So as soon as I create a wiggling magnetic field, that means I have in fact both a wiggling electromagnetic field that is a wave of electromagnetic light. So So that's it.

[00:05:36]The way I can make an electromagnetic wave is by wiggling some electrons. Who knew that the same physics we learned way back when for generators and motors is in fact the way to generate light waves. Okay team, we're going to go to a FET website. It's an older FET website, but still great and it will do a good job visualizing this. Link in the description below. Thanks as always for FET. It is going to have kind of an old school setup of like a like an oldtimey radio broadcast. Like if you're in a car and you listen to an actual radio station, 97.3. There are places that produce a radio signal using a large antenna and then your car has an antenna. On the website, they're kind of using like like a big broadcasting antenna on the left and then like imagine someone has a house with a smaller antenna connected to the house.

[00:06:17]Maybe this isn't a perfect match for our current technology, but it does do a good job of simulating what is physically going on. Before we go to the website, I want to show you a model of a simplified version of an antenna.

[00:06:26]Antennas are a bit more complicated and in fact there's a wide variety of antenna types, but just to get the point across, the antennas, they they use metal and if you remember, metals are made of atoms. In fact, all all things are made up of atoms and atoms have electrons. So, in the metal antenna in the website that we're going to go to, it is filled with in fact billions upon billions of electrons. The website's just going to show one because it's easy to focus on just one, but recognize it's in fact filled with many, many electrons. And why was that important?

[00:06:51]Well, what we saw not too long ago was that if you can make electrons move that makes a magnetic field. And again, once you get a magnetic field, you create a combo of electric and magnetic field, that is a light wave. So, let's go to the website and see this in action. So, here's the website, everybody. This is our broadcasting station. So, this is the antenna that's going to create like a radio wave. And then this, again, it's a house with an antenna, but it could just as easily be your car and your car's antenna. This could also be one phone sending a digital signal to say a cellular tower or or vice versa. Okay?

[00:07:19]Or this could be one walkie-talkie sending a signal to another walkie-talkie. We got our metal antenna which is filled with electrons. Here is one electron right here. Let's see what happens when I grab the electron and I wiggle it. Okay, I'm going to move it up and then I'm going to move it down. Do you see what's happening when I wiggle that electron? This is representing a simplified version admittedly, but we learned that moving an electron makes a magnetic field that creates an electric field. Those two things go hand in hand.

[00:07:42]By wiggling an electron, I create an oscillating electric and magnetic field.

[00:07:47]That's a light wave. So, in fact, me wiggling an electron up and down, back and forth, that's going to create a essentially wave of light, an electromagnetic wave. And team, it's tough for me to do kind of both at once, but as I'm wiggling this electron over ahead on the left hand side, I'm going to pause. Look over here. It's tough to see, but this electron is wiggling up and down in response. When the wave is done, this electron isn't moving anymore. I'm going to change the simulation to to oscillate just so I don't have to wiggle it back and forth.

[00:08:11]Everybody, it looks like this wave is going backwards. It's it's in fact not really. The field is an electric force and the force is causing the acceleration. So when the electron is down here, it's going to be pulled upward. When it's up here, it's going to be pulled downward. So in fact, this wave does match, but it looks kind of backwards. It's beyond the scope of our our class, but regardless, wiggling an electron is going to make this oscillating electric and magnetic field.

[00:08:32]They're just showing the electric field part for simplicity. That wave is traveling outward, and when it gets to this antenna, it causes this other electron to react. Again, it looks like it's backwards, but these are not like like ducks sitting on a water wave. This is a force that's about to pull the electron down and then the force is going to pull the electron up. So it does in fact match reality but but it looks a little weird but nevertheless when I make the radio wave on the left hand side and it travels outward the electron over here is going to respond.

[00:08:56]If I end the oscillation okay so now no more movement. So no more changing electric magnetic field. The electron is stopping to move. It's not going to move any further. Okay. It's going to come back here and then it's not going to progress anymore. So I'm back over here on my slideshow and there's a lot on my screen but we already saw most of it.

[00:09:11]Again, the website focused on one electron, but by moving an electron up and down, that is going to create a magnetic field, and that instantly gets us with an electromagnetic field, an electric and magnetic wave that can propagate outward because you can't have one without the other. Now, you might be thinking, how can I make these electrons wiggle? On the website, I used my mouse and I wiggled it up and down. But in real life, everybody, we learned that electrons are used in electricity and we can make electricity flow one way or another. Maybe imagine I'm holding a battery and maybe the battery, this is obviously simplified a little bit, but imagine the battery was connected down here. Do you remember batteries have a positive and a negative side? So imagine I have the battery and when it's attached one way, it causes these electrons maybe to drift upward and then I flip the battery around quickly. If I flip the battery around, so then it's on the opposite pole, the electrons might then attract and then repel and then attract. Flipping the battery back and forth can make the electrons move back and forth. Or if you have an alternating current, it can make these electrons wiggle up and down. So from a technology standpoint, we can make this wiggling happen and that creates our radio wave.

[00:10:08]Okay, this wiggling creates this electric and magnetic field which propagates outward. Now everybody, there are in fact many types of antenna. Here I have just an image I found very quickly on Google with six different types. How they work specifically can can very quickly become complicated.

[00:10:22]They work in different ways based on what your goal is in terms of like directionality, how powerful you want the signal to be used for, the type of wave, radio or microwave. So so there's a lot of things that complicate this. We are in this video focusing fundamentally on what is actually happening. Electrons wiggling. And that is true for all six of these. They are all based on the idea that you make electrons wiggle. And why would we want to do that? Because of the connection of electricity and magnetism.

[00:10:44]Wiggling electrons make a magnetic field which immediately creates these electric and magnetic field waves that propagate outwards. It's also worth mentioning everybody very quickly if you've been thinking like well uh Thrasher how are we actually sending the the podcast? How are we actually coding the text message?

[00:10:58]That's just beyond the scope of this video. This video is going to be long enough. If you're in my own class, we're going to learn a little bit about how we attach information to these waves in the future. So again, we're just focusing on we want to send a radio wave, what this process overall is. So last couple of slides, team, and then I'm done. Thanks for staying with me. All right. Again, we started off with this very basic and simple antenna. In the last page, you saw that these antennas can be very these I have some early smartphones and there's an antenna here. In fact, some of these phones you could actually like grab this little piece and you would extend the antenna and again on this antenna, you would have electrons and the phone would wiggle electrons back and forth. Maybe you would think like where are the antennas in modern smartphones and team they've kind of creatively from an engineering perspective they have hidden the antennas but they're absolutely still there your Chromebook your smartphone your laptop even like a desktop they all have antennas in them if they're using wireless communication whether that's like 5G or Wi-Fi in your phone and I know this says iPhone 4 and if you're watching this in 2026 or after obviously we have more advanced smartphones but nowadays they often hide the antenna in plain sight if you have your smartphone nearby check and See, if on the edge you see these pieces of metal and especially if you see these brakes because the antenna is often the outer casing of the phone, imagine right here we have wiggling electrons. In fact, when you hold your smartphone up to your ear, you are probably touching the antenna and there are wiggling electrons nearby.

[00:12:13]Sometimes they're inside the the phone casing themselves. So, they're not always on the outside, but there are antennas. And in fact, because there are different forms of wireless technology, your phone has in fact several different antennas that are being used depending on whether it's for Wi-Fi or like cell tower communication, things like that.

[00:12:27]We spent all this time talking about the creation of the radio wave, how did that second house on the website or how does your friend who is receiving the message or maybe that the cell tower that's receiving your text when you first send it, how does it pick up that radio wave or that microwave? Well, everybody, it's still based on this idea that a wave of light is a combo of electric and magnetic fields. And remember, the antenna is still made up of a whole bunch of electrons. Everybody, how we are receiving a signal is based on again these bullet points. What happens when this wave of light and let's maybe focus on the electric field. What happens when this blue electric wave of light, electric field passes by the antenna?

[00:13:04]What does an electric field do?

[00:13:06]Everybody, did you notice this first bullet point? We learned way back when that electric fields, they move electrons. So, I'm not going to go back to the website, but if you remember when the radio wave got to this antenna, the electrons started wiggling. The reason it did that is because a wave of light includes an electric field, and electric fields move electrons. So this electric field when it passes by, it pushes the electron up and down and up and down.

[00:13:29]And then the radio uh uh uh amplifier in your car or your phone itself or the cell tower, it uses other electronics to decode those wiggling electrons. But those wiggling electrons can be used to send a message that will then be picked up say by the computer. Okay, but that's the idea. All right, let's put this all together in one slide to summarize. Here again, I have kind of my broadcast.

[00:13:48]Maybe this is a radio station. Maybe it's your smartphone when you're sending a text message. over here. Maybe this is a home listening into a radio broadcast or a car or maybe it's the cell tower that's going to detect the signal that you just sent via Snapchat. And here is the radio wave that's being sent from one device to the other. How are we broadcasting? Well, we are causing electrons in an antenna to vibrate up and down because we learned before that moving electrons create a fluctuating magnetic field that in fact creates both a magnetic and electric field. And that is a wave of light. Okay, say that is a wave of radio light. It could also be microwave or infrared, but that's it.

[00:14:21]That's how we get this wave in the first place. And then how do we receive this radio signal? Or it could again be a microwave signal. How do we receive it?

[00:14:27]Well, all light signals have electric fields. That's the blue part in this little animation right here. That electric field we learned will move electrons in another antenna somewhere in the distance. Electrons in an antenna will oscillate back and forth from that electric field. That wiggling electricity, that moving electrons that will travel to the speaker. Remember when we learned how speakers respond to electrons wiggling back and forth because moving electrons make a magnetic field and that will wiggle wire nearby magnets? We learned that's how speakers work. So imagine you had a speaker right here because you're listening into your favorite music radio station or again it could be like the CPU of the smartphone or the cell tower has computer components as well that can decode this signal. But that's how we are creating waves of light to be used to send information from one space to another.

[00:15:08]All right, it's still based on these same fundamental links between electricity and magnetism. And that's what I think is so cool. We've seen this connection being used from an engineering perspective for a lot of human technology. It is again being used here how we send information wirelessly.

[00:15:21]Everybody, this is the way we send information whether it's the early 1900s with early radio. This is what we did.

[00:15:26]We wiggled electrons in a certain pattern that made light waves in a certain pattern that wiggled electrons in another antenna that sent sound or a radio broadcaster's voice. Walkietalkies do the same thing. your remote control.

[00:15:37]If you have like an old tiny remote control, a basic remote control, it uses infrared waves, but it again does it by wiggling electrons. Your phone communicates with a cell tower. That's kind of the next step after you send a piece of information. Or the cell tower is sending you information when you're scrolling through Tik Tok. Again, by wiggling electrons, which creates a signal that your phone then detects.

[00:15:55]Your PS5 controller, it sends information to the console by wiggling electrons. You don't see the antenna in the uh game controller because it's inside the casing. your computer whether it's connecting via Wi-Fi or Bluetooth it has antennas that are wiggling electrons and the nearby router is receiving and also broadcasting based on this movement of electrons to send or pick up oscillating electric and magnetic fields everybody also like radio astronomy radio waves are not limited to human-made things when we look up at the night sky lots of things naturally produce radio waves so we make big old radio telescopes using radio waves have a lot of advantages I won't get into them here this video is long enough but it is again based on the same thing when radio waves from outer space from distant galaxies, from distant stars, from gas clouds. When they travel the billions upon billions of miles across space and they hit this satellite or this telescope, it wiggles electrons which we can use de and we can use to decode information to learn about these things in outer space. So very cool how we use again this link between electricity and magnetism to both understand our universe and to design modern wireless technology. As always, thanks a lot for watching this video.

[00:16:56]That's enough for me. I'll see you again next