This is absolutely such an awesome intro in RF design, the whole series is truly a gift. There is no other single source on KZread that covers such a wide range of RF design topics. Thank you for sharing this.

@MegawattKS

2 жыл бұрын

Wow, thank you ! Great to know that it helps. It's kind-of a swan-song to the course that its based on - which students always enjoyed (after a lot of hard work on their part).

This is pure gold. I used to be a radio tech for the military but have been out for a while and needed a refresher for an upcoming test. I love when someone is smart enough to give such an advanced topic in an easily consumable manner. Thanks for your hard work!

I can't believe this quality of condensed information is finally on the platform. I have so many notebooks and books and digital notebooks. I can't remember where I stored everything. I was smiling all the way listening to this.

@MegawattKS

2 жыл бұрын

Thank you so much for the kind words. It is really nice to hear when the 'lectures' are helpful. So glad to hear it was enjoyable to listen to. Thank you !

This is amazing. Nobody really has done such style ("explain-by-building") series for fundamental radio circuits before.

@MegawattKS

2 жыл бұрын

Thanks. This was from a coordinated lecture+lab class which I agree is perhaps the best way to teach stuff. Glad you enjoyed it !

This is fantastic!! Thank you so much for taking the time to do this

@MegawattKS

3 жыл бұрын

Thanks for the feedback. Glad it was helpful !

Great presentation! Thanks for sharing.

👍 Thank you for doing these tutorials. Looking forward to watching some more.

@MegawattKS

2 жыл бұрын

Glad you like them!

Outstanding, can't wait to watch the rest, 73

@MegawattKS

8 ай бұрын

Thanks. Glad you found the channel! Welcome. 73

Thank you, Dr. Kuhn. I've set a personal goal of building my own transceiver before allowing myself to test for Extra, so this is perfect. There are some really excellent resources I've found, but this looks like the one most suitable for my level. Very succinct. Almost as if you've been teaching this your whole career ;-) 73, sir and God Bless

@MegawattKS

7 ай бұрын

Thanks Mark ! And good luck on the Extra Class exam. I actually never upgraded to that. I'm still 'Advanced' class. Nostalgic if nothing else :-) 73's

Yes..thxs!

Thanks for this amaizing series!

@MegawattKS

Ай бұрын

You are very welcome. Thanks for leaving this comment !

Very fun to get a refresher on all this :) Hard to believe it's been ~12 years since I took this class!

@MegawattKS

3 жыл бұрын

Hi Bryan ! Thanks for the note. Great to hear from you. Hopefully these videos will help 662 live on :-)

Thanks so much for this! Just what I was looking for.

Fantastic. Thank you

@MegawattKS

8 ай бұрын

You're very welcome. Thanks for leaving the comment.

Thank you. This is excellent stuff. I wish I'd found it 2 years ago.

@MegawattKS

10 ай бұрын

Glad you found it now and it is useful. Here's a companion website with the slides as well as other related series if you're interested. ecefiles.org/

Thank you very much for putting this material together. It is really inspiring to begin with RF. I like the approach where is a good balance between theory and practice. I am planning to follow this course, including the Antenna Briefs. And to build a FM radio. Thanks again!

@MegawattKS

Жыл бұрын

Wonderful. Thank you for the feedback / comment. I'm glad to see it is helpful. Both series have their origins in university coursework and I was fortunate to be able to teach senior design courses which had a laboratory basis. When I retired, this was a way of continuing that mission 🙂 If you are interested, I built a companion website to make the slide-sets available, as well as other associated materials used in the courses. (The website is not fancy, but the materials are there.) ecefiles.org/

@ernestb.2377

Жыл бұрын

@MegawattKS I have seen the website 👍 I have seen that you are retired, but I have to say that your voice sounds very very young, like from someone in the 30-40 😀 Also your voice is calm and clear. You are a "real" teacher and one can tell. Keep up the good work sir! All best from The Netherlands.

excellent series, thank you really much for taking the time in doing such a great job.

@MegawattKS

2 жыл бұрын

You're very welcome. Hopefully the next two in the series will come out well too. Mixers are up next...

Good video, thanks .. can't wait for the next

@MegawattKS

3 жыл бұрын

Thanks for the feedback. Working on part 2 now. Hopefully will get it done sometime in the coming week :-)

Great initiative Sir, Thanks!

@MegawattKS

Жыл бұрын

You're very welcome !

MegawattKS, very excited about this series. Can't wait to tell the club members. 73 W6MGV

@MegawattKS

3 жыл бұрын

Thanks for the encouragement. The series as a whole may come out a bit slowly, but the goal is to get a half dozen or so done in the coming months. Part 2 of this one should be done in a week or less, I hope. 73's

Wow this is so exciting. I love it. Thank you. 73

@MegawattKS

2 жыл бұрын

Thanks !

Amazing content! The mouth noises in the mic really bothered me a lot, but if I turn the volume down almost completely and then turn on subtitles I can get through it. It's a personal issue of mine for sure, but the content is so good that it is worth it.

@MegawattKS

2 жыл бұрын

Thanks for the comments. There is a technical issue with the audio in this episode (and maybe one or two others). The microphone has a volume knob and I think it may have been set too high in some segments. Hopefully most of the other videos might be a little better, as I turned the mic down once I realized this. I've never tried the subtitles, but that sounds like a good solution. Glad KZread added those.

@kurchak

2 жыл бұрын

@@MegawattKS yeah I realized after I continued on that it was mostly just this episode that had that specific sound issue for me. I'm so glad I continued! The other ones seem better. It's an issue I run into a lot. I've just got something wired wrong upstairs lol.

Hi, one (novice) question about bandpass filters. For example if we have a parallel LC circuit between the source and the load. At resonant frequency the Z0 of this LC circuit goes theoretically to "infinity", and the source of 50 Ohm "sees" only into the load of 50 Ohm, so good impedance match there, no reflections. But at every other frequency (different from f_resonant) there would be a mismatch between the source and the circuits in the direction to the load. Does the source have problem with reflections in that case?

@MegawattKS

8 ай бұрын

Yes. Good observation! The filter is actually "reflective" out-of-band. Meaning, it's not too bad over the filter bandwidth, but outside the filter bandwidth, the impedance is very bad as seen from the source - so it has strong reflections. Another way to think about this is through power conservation. Inside the passband, the power gets to the load, so little reflection. Outside, almost no power gets to the load, so almost total reflection. Occasionally, designers create "reflection-less" filters, but it's not common. For more, and for cases where the reflection can become somewhat of a problem, see here: www.microwaves101.com/encyclopedias/reflectionless-filters

@ernestb.2377

8 ай бұрын

@MegawattKS Thanks for a quick feedback. I realize, the most filtering is done on low power signals anyway, and impedance mis-match wouldn't be a problem. And small sognals are first filtered before amplifying, where impedance mis-mach would be a problem.

I am a digital PCB designer, I am studying EMC, and I see that many notion come from the RF world, Digital's frequencies gets higher and higher and it tends to become harder than RF since frequency spectrums are continuous! I am a zero at RF, So I'll give your course a try, do you think it is a good start for a noobie ?

@MegawattKS

5 ай бұрын

Honestly, I think the Antenna Briefs series is probably better for the goals you stated. Here is a relevant section in Episode 8 in that series: kzread.info/dash/bejne/kXuewcqifdXKn84.html . I've keyed this video up at the EMC section, but after watching from this point to the end, you might want to go back and watch the whole thing and/or some of the other videos in that series. In particular, Episode 1 that talks about wavelength. EMC is quite a big area, but in PCB design, it's mostly about having ground planes to keep the EM fields confined, and when that doesn't completely work, using shields. Indeed, with a good ground plane (or power plane) below top or bottom metal interconnect traces in a 4+ layer board, the traces become "transmission lines" and emission is pretty well controlled. That's why the normal stackup for 4-layer PCB is trace-layer, ground-layer, power layer, and trace layer. Two layer boards work as well, if one layer is devoted to a ground flood as shown in the video. Hope that helps.

@AlbertRei3424

5 ай бұрын

@@MegawattKS I didn't know about that antenna series, awesome! Yes, PCB design is the basis of having a good EMC, but I want to get beyond that level, just watch a webinar of Keith armstrong and you'll see what I mean. Regarding your stackup, you're right that having reference planes is the basis of a good EMC board, but beware of using PWR layer as reference plane, if the PWR layer is segregated (many splits), routing across them in the adjacent signal layer might result in slot antennas and cause radiation issues... Therefore, SIG/GND/GND/Sig is often a better alternative, with routed power. If power can't be routed and need plane for Power integrity, then usually you need more than 4 layers anyway... Anyway, EMC is a big topic as you said, I'll give a try at your RF courses 🙂

@MegawattKS

5 ай бұрын

@@AlbertRei3424 Thanks for flagging the issue with the power plane. Agreed. I was thinking of a single flood, but I guess that's not very realistic with multiple voltage rails in digital systems. Good description of the problem ! We definitely need the return path of the trace transmission lines to be unbroken at least if the breaks are comparable in size to the wavelengths of concern. I'm watching some of the Armstrong and related stuff. Found them here interferencetechnology.com/category/technologies/shielding/ . Thanks for that reference. Do you have/use EM simulators and near-field probes? EMC is not my main area, but I've spent some time at IEEE EMC conferences and noticed that they love EM simulation. Anyway - hope the Antenna Briefs series is useful, or at least an interesting angle on RF material 🙂

@AlbertRei3424

5 ай бұрын

@@MegawattKS Just to add something about the pwr plane as a reference plane. Even if you only have 1 voltage and thus a solid pwr plane, you'd prefer using ground for that plane, because return current ultimately want to get back to ground, and when they get to it through the PWR plane, they'll eventually have to go through either: - The stray capacitance between GND and PWR planes - More often, through a bypass cap between PWR and GND Both of the case are not ideal because they have an increased impedance compared to a straight short to ground. Above 100Mhz, 1ghz, bypass caps have too much impedance because of their inductance, and the stray capacitance is not ideal neither. Increased impedance in the return path --> Ground Bounce --> Common mode generation --> EMI issue! For the EM simulation, I have never done one EM simulation yet, I think you need to work in a company that have these software because they are expansive . But yeah when I read Eric Bogatin, Keith Armstrong, and other, it seems that digital design won't be possible in the future without field solvers 😂

@MegawattKS

5 ай бұрын

@@AlbertRei3424 Agreed on the power plane issues. And we can always go to 6+ layers if the routing needs it. On the other topic, people shouldn't feel they have to have EM solvers. There is way too much effort put into simulations these days IMHO. It is and always will be possible to design using analysis, reasoning, and test, even without a sim. And arguably it can result in a faster design cycle for some cases, if the reasoning is done well 🙂 (Oh - and frequency scaling in reasoning is an invaluable tool :-)

I have really enjoyed your videos! KO4ZFE

@MegawattKS

3 ай бұрын

Glad you like them. 73 !