Antenna Briefs #1 - Frequency, Wavelength, and Size

Рет қаралды 15,202

Күн бұрын

This is the first in a series of videos on antennas and how they work. It is based on and supports a university course, but covers material without any deep math. In Episode 1 we overview key elements of radio antenna operation and signal propagation. We start with the first antennas created by Hertz and proceed to demonstrations with modern antennas - focusing initially on dipoles. Additional types including loops, monopoles, and dish antennas are covered as examples of real-world antennas and are presented across the frequency range from 1 MHz to 40 GHz. The key takeaway is the formula for wavelength and how it relates to frequency antenna size (and directivity).

Пікірлер: 40

@W1RMD 11 ай бұрын

You've done an excellent job at condensing a very large amount of material into under half an hour. I can't wait to continue further into this series. Thanks and 73's!

@MegawattKS 10 ай бұрын

Thank you ! Hope the rest are useful too. 73

@michaelgallias2651 2 жыл бұрын

Thank you for the wonderful video. Finally someone who explains those things simply, with many photos. Looking forward to the next one.

@MegawattKS 2 жыл бұрын

Awesome, thank you!

@aerofart Жыл бұрын

Watching your videos has brought me so much closer to understanding the mysteries of radio magic. Thank you for your monumental effort!

@MegawattKS Жыл бұрын

You are very welcome. Glad to hear it's appreciated.

@sullivanzheng9586 2 жыл бұрын

Another series that fits exactly what I need! Just finished my first AM/NFM/SSB SDR based on your radio design 101 series now it is time to kickstart my antenna project.

@MegawattKS 2 жыл бұрын

Neat !

@fm71450 8 ай бұрын

Thank You! I took physics 45+ years back - the concepts have been utilized often since then, but NOT the math. Your explanations are very clear, and greatly appreciated. So much to learn!

@MegawattKS 8 ай бұрын

Glad it helped!

@fjs1111 2 жыл бұрын

Such a great amount of information on antennas in a short time. Thanks

@MegawattKS 2 жыл бұрын

You're very welcome. Thanks for the feedback. That is the goal - packing in the key stuff without getting too deep :-)

@johnburns6422 29 күн бұрын

This is just what i like , thanks

@maksberlec4832 2 жыл бұрын

Gooood! I think I'll watch the serlies again and again.

@julienpoivret6013 2 жыл бұрын

Thanks you for crystallising the true natural aspect of light. a very good and sharp explanation.

@MegawattKS 2 жыл бұрын

Glad it was helpful. Thanks for the comment.

@josecarlosribeiro3628 7 ай бұрын

What a beautiful class, Professor!👏🏾👏🏾👏🏾 Congratulations, God bless you and Marry Christmans! Jacareí-Sao Paulo-Brazil.

@MegawattKS 7 ай бұрын

Thank you. Merry Christmas and happy holidays from the US !

@caseylocke4474 20 күн бұрын

This is a great video and I appreciate you breaking it down so well. I'd like to make a small suggestion and please, please, please don't take it the wrong way. I promise I'm not trying to be nit picky. I'm a sound guy so these are the terms I think in. In future videos, you might consider addressing some of the mouth noises issues. There's a lot of mouth and lip smacking between sentences. That can usually be addressed by rinsing the mouth and then having some hot tea before recording. :) Just a thought. Thanks again!

@MegawattKS 20 күн бұрын

Thanks. I noticed that too, but only recently. Hopefully you and I are more sensitive than most 🙂 I did notice that if I turned the volume lower, it was OK. Will try the solution(s) you mentioned before making new videos going forward (July 2024). Maybe KZfaq can create an AI filter to get rid of these artifacts in the existing ones ? ;-)

@lama6542 Жыл бұрын

hello professooor!!! was stumbling a bit through my capstone project concerning a switching rf circuit. thats because I think the fundamentals of RF and antenna did not really click. I found your youtube channel then your website and man!! i always wanted a great source that helps package the material of rf for me. and just taking a look at your website. I have hw to do! thanks a lot for the help 🙏🏽 i am excited to get started

@MegawattKS Жыл бұрын

Excellent. I'm really glad it helps - and that you found the Website too. Thanks for letting me know !

@benoitraulin1264 8 ай бұрын

Thanx a lot, my next course (il France) wil, I hope, have the same level of science a good sense.

@thomasmock9186 2 жыл бұрын

Thanks, great video!!

@MegawattKS 2 жыл бұрын

Thanks !

@jamescopeland5358 3 ай бұрын

Very good

@MegawattKS 3 ай бұрын

Thanks!

@richardphillips2405 Жыл бұрын

This is great. One hope that I have is to understand about actually measuring rf exposure inside of the near field rf from the transmitting antenna.

@MegawattKS Жыл бұрын

Thanks. Sorry, I don't have any experience with measuring near-fields, but episode 5 does talk a little about how to estimate E-field strength analytically in a free-space environment. I tried to be careful there to emphasize that it's only far-field however. In episode 6, the plan is to briefly cover some equations for near-fields and how that's done in general in simulators, but probably not measurements unfortunately. Near fields are pretty complex and exposure studies are outside my area.

@richardphillips2405 Жыл бұрын

@@MegawattKS I know. But, I think that your videos will help me with understanding about E fields and H fields. Thanks again for a great video.

@dominicestebanrice7460 7 ай бұрын

This was SO helpful. For a young person interested in this field and thinking about college, what is the optimal route into the wireless communications field? Is it better to do a general four-year bachelor degree in physics or electrical engineering or should one just dive in and try to enroll in a telecoms or RF engineering specialty program?

@MegawattKS 7 ай бұрын

Glad it is helpful ! For one interested in the wireless field, I would recommend electrical engineering (but please get multiple opinions/viewpoints). My reasoning is that EE opens up a very wide field of applications whereas physics tends to focus mainly on the theoretical underpinnings that support engineering. I have also known some people who got physics degrees but found employment more difficult. I'm not against physics - I love it - but the communications field involves a vast set of topics and technologies that are really part of engineering. The second part of the question is harder. I think it may depend more on the schools you would consider and what they offer. In the US, comm is still part of EE. But, some schools do offer "focus areas" to target something like comm more early on in the program than they did when I went through the programs. Hope that helps. Again, get other opinions for sure, and look at different schools you might consider to see how their programs are set up. Enjoy the journey !

@byronwatkins2565 2 жыл бұрын

Curved wavefronts typically do not have E and B in phase, but plane waves must have.

@MegawattKS 2 жыл бұрын

Thanks. I will look into the near-field solution more and see if there's a way to improve the graphic there in the future. It's definitely a jumble in that area in reality. Do you think it's an OK approximation as shown close to the feedpoint where V and I sources are in-phase?

@ahmednor5806 6 ай бұрын

🙏💐💐✔️

@noluck33 Ай бұрын

STOP the Ads, as most ads have Malware and are killing computers!!!

@MegawattKS Ай бұрын

The ads are placed in KZfaq videos by KZfaq, and we have no control over them (unless perhaps a channel is monetized, which this one is not). That said, I don't think there's a plausible mechanism for infection if you don't click on something to follow a link somewhere. AFAIK, ads are just other streamed video - not software. Hope that helps.