Antennas Part I: Exploring the Fundamentals of Antennas - DC To Daylight
ฝัง
- เผยแพร่เมื่อ 14 พ.ค. 2024
- Derek has always been interested in antennas and radio wave propagation; however, he's never spent the time to understand how the wiggling of electrons in a wire can actually produce RF radiation.
So, in this theory-based episode of DC to Daylight, Derek discusses antenna physics, shows how a dipole antenna radiates RF, and demonstrates how that RF behaves with a receiver antenna. And, where Derek needs some help with the details, he calls in an expert, Sterling Mann, who works in the field of RF. In the next application-based episode, we'll build our own antenna and use it to communicate around the globe!
Watch the full interview with Sterling Mann and ask Derek questions on the element14 Community! bit.ly/3IIVEKl
Engage with the element14 presents team on the element14 Community - suggest builds, find project files and behind the scenes video: bit.ly/3tmdewv
Visit the element14 Community for more great activities and free hardware: bit.ly/3q6YMpu
Tech Spotlights: bit.ly/3qPrDhM
RoadTest and Reviews: bit.ly/3pV5Bux
Project14: bit.ly/31wbnJY
#0:00 Welcome to DC To Daylight
#1:20 Antennas
#3:05 Sterling Mann
#4:05 What Is an Antenna?
#6:18 Maxwell's Equations
#9:25 Sterling Explains
#12:55 Give Your Feedback
#antenna #antennas #radiofrequency #maxwellequations #dipole - วิทยาศาสตร์และเทคโนโลยี
Watch the full interview with Sterling Mann and ask Derek questions on the element14 Community! bit.ly/3IIVEKl
So much to learn here. Looking forward to part 2!
Thanks! It's quite a lot of information to cram into one video, so we needed to split it up. Yes, part 2 is coming soon - and as usual, there will be an application video to follow. Happy to have you! -Derek
We really appreciate you, future Derek
Thanks 7Alfa - I always appreciate your supportive comments.
Really appreciate your efforts. Keep it up and waiting for Part-2 🤟
Thanks Derek for sharing. Antennas have always been captivating and fascinating. As hams, they are perhaps one of the best parts of the hobby to experiment and laarn from, and I encourage ALL to build their own when they can. 73
Very nice presentation
Thank you for this video. I did have trouble in understanding the section on Maxwell's equations. I will have to spend some time on that.
The best explanation of antennas.
Thanks Glen. -Derek
That was great... much more of that please! :)
Excellent... You got it! -Derek
Thank you for the informative presentation.
Derek is sporting a sweet looking hat. 🤘
Hook 'em! -Derek
Yeah, antennas have always been "black magic" to me, now they are "magic". Looking forward to part 2. I am learning a lot from your channel - thanks!
That's awesome to hear that it's more understandable now - so glad you are here. Believe me, this is one of those topics that I still have difficulty wrapping my head around, because I can't see the thing! More cool stuff in the pipeline so make sure to come back. -Derek
I had a hunch about this information but now it's all so crystal clear.
Thanks. I hope it was helpful. More practical antenna content is coming in part II. -Derek
Wow so well explained 👏
Thank you! -Derek
Great tutorial 👌
Thanks Hagop. It was fun.. Keep coming back, because we're going to talk more about antenna engineering and after part II there'll be the application video which is going to be a blast. -Derek
Great job Derek 👍
Thanks for checking in!
Yay! Calculus and linear algebra!
Not tooooo much though. -Derek
great explanation ! ♥️🇲🇦
Thank you! -Derek
very kewl :) like such topics
Thanks! -Derek
WHERE IS PART 2!? Not out yet? Nooooo, can't wait!
Thank you, my favourite part was at 11:00.
It's in the pipeline.. The animation *is* mesmerizing. Thanks for the feedback. -Derek
Second part pls
“Assuming *your* earth is spherical”
Hahahaha! Nice burn.
How do you power the antenna? How do you recieve the power in the receiver?
Any possibility to explain its mathematical derivations
at 8 min it almost started then back to chatting with friend about arithmetic and a bit of math
I would like to ask you for help on measuring rf field strength. Is there an accurate way to measure the rf field where the location is inside of one wavelength? I would like to measure frequencies that are in the hf amateur radio bands starting at 1.7 mHz and going up to 30 mHz. Do I want to measure the e-field or the h-field? I think that the e-field would be easier to measure. The equipment I have is a Siglent spectrum analyzer which I believe to be accurate and I have an older field strength meter, EFS-1, which works but I am not sure about the calibration. I read a paper from Keysight Technologies which describes how to use a spectrum analyzer to measure the e-field. (859xE: How Do You Measure
Electric Field Strength with an
Antenna and Spectrum
Analyzer?) I'm not sure about what they call the antenna factor which gives volts/meter in terms of dB's. I checked into buying an accurate rf field strength meter that can measure lower hf frequencies. I found them to be very expensive. What is driving this project, is the FCC requirement to measure rf exposure around the amateur radio station. The ARRL has an online rf exposure calculator. I have several unknown factors at my station and I would like to be more accurate. I also want to learn more about rf fields. Thank you.
The discussion of the transition from separate E and M fields in the nearfield to an EM field in the farfield was a little muddled. The discussion in wiki is pretty good. One picture that is missing is the transition from either a high characteristic impedance at the antenna-free space interface from a dipole, or the low characteristic impedance from a loop antenna to 120 x pi (377 Ohm) free space impedance. This is shown in Henry Ott's book on EMI...
Ott's book is a fantastic read. Highly recommend to all interested in EMI or radiated/conducted emissions and good info on layer stackup. Yes what you mentioned is missing. However, it's always difficult to determine how deep to go on a subject. Maybe in the future we can dig even deeper. -Derek
What intrigues me is how do electric field flows in an open circuit. It shoudn't a close circuit to electric field to flow?
8:20 No, an electric field can indeed exist without an magnetic field, and vice versa. The time term in Maxwells 3. and 4. equations just tells you than when one field is changed over time, the other is induced.
Outstanding info. When future Derek had the Sabbath shirt on, he was awesome! Just sayin...
Thanks Jim! That future guy is a troublemaker. (And we only talk about future Derek in future tense) 😁
The simple reason why antennae produce rf is that the driving signal is accelerating electrons in the aerial conducting material. accelerating electrons radiate electromagnetic radiation.
Hi Andy. Thanks for your comment. Unfortunately, I have trouble with simple reasons! 🙃
True, accelerating charged particles radiate RF, (intended and un-intended radiators) but I thought it would be fun to look under the hood of Maxwell (or maybe it was just an excuse to talk to Sterling). 😀 -Derek
9:25 "Sterling Explains". Hahahaha. yeah. Sterling doesn't know, but it took him a long time to fail to say it.
At about 02:02 in this video:
*_"Ah, nuts...."_*
🤭🤭🤭
Halfway decent
Thank for your video, but vital info seems to be missing.
As in most rf videos.
Still a good video though
That is great to hear! I didn't want this to be the same format as most other antenna videos.. and I've watched quite a few. Make sure to come back for part II and maybe some of the missing vital information will be there. -Derek
Integral? I do enjoy a good calculus pun.
e to the x was at a party for math functions and tried to integrate. It didn't make any difference.
Ha! My wife says pi r squared. I say they're round. -Derek
@@AmRadPodcast Pi and 22/7 were roommates, and they constantly got on each others' nerves, as roommates are wont to do. At one point, 22/7 asked Pi "Why do you have to be so irrational?!" Pi retorted "Stop repeating yourself!"
@@petersage5157 😆
J is not displacement current, mu0 de/dt is. Also an E field can exist without a B field, just not a solenoidal one.
Thanks for your comment. I think the viewer understands that when we're speaking about E and B fields coexisting, we're referring to an electromagnetic wave.
@@AmRadPodcast There is also an error in the equation 8:28 - there should be no factor 1/c^2. This factor, or epsilon0*mu0, is to be found in the wave equations derived from Maxwell's equations: (1) Nabla^2*E-epsilon0*mu0*(de^2_E/de_t^2)=0 for electric field and (2) Nabla^2*H-epsilon0*mu0*(de^2_H/de_t^2)=0 for magnetic field. Because there is formula epsilon0*mu0=1/c^2 for the speed of light in vacuum we can also write Nabla^2*E-(1/c^2)*(de^2_E/de_t^2)=0 and Nabla^2*H-(1/c^2)*(de^2_H/de_t^2)=0.
Greetings from Poland!
@@erykbaradziej3639 This is wrong, The video is using SI units, The factor is correct.
@@JensenPlaysMC Oh yes, you're right, excuse me. But I know different form of the equation (that is in a Polish book for students of electronics) which I mixed up with that of 8:28. The version is: Nabla x H = J + de D / de t where there are different vectors: H which is B / mu or B / mu0 in vacuum and D which is epsilon * E or epsilon0 * E in vacuum. This form is more clear in my view and it corresponds well with the previous Maxwell's equation: Nabla x E = - de B / de t . I also found a form: Nabla x B = mu * (J + epsilon * (de E / de t)). If we factorize this we achieve mu * epsilon or mu0 * epsilon0 which is mu0 * J and (1 / c^2) * (de E / de t) as in 8:28 because mu0 * epsilon0 = 1 / c^2.
School never end? We thought we've left school, but no!
Never stop learning! Pull up a chair. 😁
U cut it there?!
Yeah, sorry had to cut it somewhere - unfortunately, that was the most natural place. However, if you hit the link in description, the full talk with Sterling is there. -Derek
Hi sir good day to you where ever you are i just want to ask a question about my ssb 710 icom why does the power supply flactuate whenever it transmit? Even other devices turn off suddenly whenever i talk.
why do you look like Tony stark ??
In vacuum 😂
Thank you for the video .. but well, sorry Sterling but the black magic is still black magic :( ...
the key thing to start with for the journey of understanding this magic is: "Kinks" ..
but guess what, although I've went through the journey of "digesting" what really happens for the em wave to propagate, I'm unluckily still not satisfied :( ...
please speak slowly. because your videos are watch by people around world, not only english speaking people. please reduce your speech speed by 30 percent. Please
Good thing you tube offers the option to change playback speed.
With the playback speed control, still not good speech. Better, the speech in you tube video be reduced by a content creator.
Typical, bait you in then here’s the subscription fee.
where do you guys make your money? you barely get any TH-cam views, you don't sell anything, there's not that much activity on your forum, ... is this just for you people to add to your resumes? i mean, great production values, but i'm just wondering what's in it for you, and why, despite seemingly working hard on this, why you're not working on getting more reach?
... Element 14 just seems kinda weird to me...
Element14 is part of the big electronics components retailer Newark, which is I believe owned by Avnet. Avent also own Farnell in the UK
Thanks, we're glad to hear that you believe element14 presents content, and the content by the video creators is worth sharing and we'd be glad to see it shared further!
element14 presents is a part of the element14 Community as we're sure you've seen the links to the Community site, and it's easy to think that not a lot happens there, perhaps because there are so many different groups and categories, but there's more than simply one forum, there're many forums, comments, blog posts and documents to get involved with, and you're welcome to take part.
As another mentioned, the element14 Community is a part of Farnell, a multi-national electronics distribution company, and Farnell is a part of Avnet. Frankly we don't typically post our products directly as links on our videos because we've responded to feedback that people don't want to see that. We can start doing that again if it's what people want, but really we want people to be a part of the Community and help Engineers and Makers to produce great projects, to inspire them, and learn and share their knowledge with others.
Thanks for the comment and taking part.
@@7alfatech860 They also own CPC in the UK too, together the organisation is probably the biggest around!
@@petersheldon3558 Didn't know that.
Just want to clarify, I really enjoy the videos they put out on this channel, esp Derek and I have not noticed any commercial bias
@@7alfatech860 I really enjoy them too, it makes a change from the video's which just want to sell you something, hopefully they keep up the good work as I'm looking forward to the next installment.
Don't split videos up into parts.