Awesome explanation... and the visuals were incredibly helpful. The use of motion From diagram to diagram was really A terrific support to help understanding the concepts.
My experience with waveguides goes back to the mid to late 60's when I operated and maintained tropospheric scatter equipment. Never understood the theory but I like your vid. Thanks.
Thank you for the video, it's a nice, concise explanation. One thing to add: the fact that the length of the choke is not constant across the broad wall helps make the match better over a broad range of frequencies. If the geometry was made exactly lambda/4 over the width of the broad wall, we'd get a good VSWR at only one frequency. Also, beyond about 40 GHz, it's common to see the UG/387 style flanges that use alignment pins to ensure that the tiny openings stay lined up. I have not come across choke flanges below WR-28 (Ka-band). I suppose the grooves become too difficult to machine.
I have forgotten almost everything I learned in microwave class almost 50 years ago. This is an awesome refresh. Like my digital teacher used to say, "RF is magic and doesn't exist".
Thanks for the comment. That's so funny about your digital teacher. Robert Widlar, the invemtor of the first opamps made fun of digital engineers, but I'm not about to. I worked around some great ones that had some amazing accomplishments.
Thanks for this. Have been working in the satcom industry for almost 50 years and have worked with my share of waveguide. Interestingly I think usage has declined a fair bit in recent years as there's an increased shift to smaller solid state power amplifiers that can be mounted closer to antenna feeds. Used to be commonplace to have HPA (high power amplifier) rooms with waveguide plumbed all over the place at gateway earth stations, but now not so much. For user terminals everything is pretty much feed mounted and you don't see any external waveguide.
Wow that’s a lot of experience. Yes that’s a trend for sure. UHF television transmitters are good examples of use, but now with everything streaming, I wonder how long terrestrial broadcast will last. Thanks for the comments.
A really clear and straightforward explanation, thanks! (And that choke flange is such an ingenious design! It seems like it would only work perfectly at a single frequency though. The waveguides themselves can be used for a range of frequencies, do they make choke flanges for specific frequencies within the range, or are they good enough across the typical range?)
Thanks for the comment. The ones with circular features have an increasing VSWR as the frequency increases. Some choke flanges have horizontal features which eliminates that issue for the most part.
This was fascinating, thank you. I'm 32 and I've spent a lot of time exploring the various long-lines towers in my area and I've never even remotely understood how waveguides worked until now. I just assumed they were like a fiber-optic pipe for radio waves, hap hazard bouncing along like a river of energy in there. As a machinist by trade, I find it particularly fascinating the relationship of the physical dimensions and tolerances to the frequencies and efficiency of the system. Can it be dangerous to send the wrong frequency down an incorrectly sized waveguide to ending up with current on the exterior surfaces of the waveguide?
excellent, I know nothing about wave guides but that helps no end. I do wonder how the ripples in the flexible concertina walls don't cause all sort of reflections, are they at 1/4 wavelength apart or something?
I don't have any experience with the flexible elliptical waveguide. I surmise that it only adds length, otherwise it would not be very useful. Thanks for the comment.
4:50, that jump to the quarter wavelength stub was jarring. I see how you were using it as a transitory, and I like how you use this as a kind of lemma to explain waveguides, but I had to rewatch it a few times to make sure I respected the explanation. If I understand correctly, the reason we have the stub was to attenuate all signals that aren't at that frequency (or integral modes thereof) and set the junction point to 0V (via a standing wave) if they are.
I get it. I'm not a fan of the imperial system. However, the standard waveguide numbers were based on inches, so I was not inclined to change. Thank for the comment.
@@oldhackee3915as much as equipment parts may be imperial, how about say for just general equations, such as 14:25 having attentuation in dB/length, such situations use metric? There isn't a need to think about the length of a waveguide in metric after all, only the cross section since that is the manufacturer "standards"
@@oldhackee3915 I'm commenting from the non-US portion of the world.. SAE is ONLY used in the US. ALL other countries, with the exception of 1 ( some Asian country which still rejects metric, iirc ), use metric. The SAE stuff may well be comfortable for the percentage of kids who grew-up within the US, in the SAE system, but all the kids who failed *as a result of* the SAE system, because the sometimes-base-12 ( inches-in-feet ) & sometimes-base-16 ( much of the rest of the SAE system is either base-8 or base-16, like ounces-in-pounds, etc ), are not served by SAE. Neither are all the people who never got passed/failed in the SAE system, because they were blessed by the metric system, in school. I'm old. I was in the Imperial system ( 10lbs water == 1 imp gallon of water ). SAE actively-harms understanding of people trying to get the hang of things, from square-zero. I've tried doing conceptual aircraft design, & SAE turns solving problems into nightmares. That the US textbooks reject metric *eradicates* much potential-creativity from our current-world's population: much more percentage of people can understand metric, than SAE, due to all the bogus fractions & odd measures. That is like having a "tradition tax" on everybody, that everybody need pay, just because it's established. The basic principle of "sunk costs NEVER justify current-spending", that the business world stuck to, is correct. We need to ditch the old archaic spellings ( I'm talking at me, here, with my more English style spellings, "colour" instead of "color", etc ), & we need to ditch the old archaic SAE calculating, because *both* damage the ability of much of our populations to learn stuff, for archaism's sake?? I'm deeply grateful to you for your contributing this video: these things were never understood by me, before, & at-least I can now get the hang of the fundamental concepts.. but equations rooted in SAE .. whether in aviation-engineering, or in electrical-engineering, they harm learning, & therefore they are only a tradition-tax. Taxes have their place ( one's immune-system consumes 1/10th of one's calories, one's brain 1/4, so those are "taxes", & the benefits of both of those is well worth it, right? ), but tradition-tax, which damages one's entire economy's innovation-*ability* .. I draw the line at that kind of thing.. Thank you for making your videos! Please consider making a metric-equivalent for each SAE version, & label them, right in their title, as metric, & you'll get fans from *outside* the US.. & those fans will be learning real understandings, which will help our world be more strongly innovating, as all the makers are more strongly innovating.. Salut, Namaste, & Kaizen, eh? _ /\ _
Best video on the subject so far. A joy to watch. Thanks a lot
Glad you enjoyed it! Thanks.
The choke flange design is such a clever idea. RF will never cease to amaze me 😄
Absolutely. I keep going back to "Be modest. A lot was accomplished before you were born"
I never fully understood these things but you helped clear up a lot of questions I had. Thank you
Glad it helped! Thanks.
Awesome explanation... and the visuals were incredibly helpful. The use of motion From diagram to diagram was really A terrific support to help understanding the concepts.
Thanks so much for the comment. I’m glad that it was clear.
My experience with waveguides goes back to the mid to late 60's when I operated and maintained tropospheric scatter equipment. Never understood the theory but I like your vid. Thanks.
Thanks.
This explains so many things and adds new questions to my understanding, thankyou
Thanks.
Thank you for the video, it's a nice, concise explanation. One thing to add: the fact that the length of the choke is not constant across the broad wall helps make the match better over a broad range of frequencies. If the geometry was made exactly lambda/4 over the width of the broad wall, we'd get a good VSWR at only one frequency.
Also, beyond about 40 GHz, it's common to see the UG/387 style flanges that use alignment pins to ensure that the tiny openings stay lined up. I have not come across choke flanges below WR-28 (Ka-band). I suppose the grooves become too difficult to machine.
Thanks so much for the comment. That's great information. Thanks for sharing.
I have forgotten almost everything I learned in microwave class almost 50 years ago. This is an awesome refresh. Like my digital teacher used to say, "RF is magic and doesn't exist".
Thanks for the comment. That's so funny about your digital teacher. Robert Widlar, the invemtor of the first opamps made fun of digital engineers, but I'm not about to. I worked around some great ones that had some amazing accomplishments.
Voodoo Microwaves
I’m in my 40s and this has been a great refresher and I love your name!
Thanks so much. Glad it was helpful.
Thanks a lot. Please Keep Coming
Thanks so much.
I used to build and test 4 port c band rotary waveguide switches...amongst others.
Very cool. Thanks for sharing.
Excellent!
Thank you! Cheers!
Thanks for this. Have been working in the satcom industry for almost 50 years and have worked with my share of waveguide. Interestingly I think usage has declined a fair bit in recent years as there's an increased shift to smaller solid state power amplifiers that can be mounted closer to antenna feeds.
Used to be commonplace to have HPA (high power amplifier) rooms with waveguide plumbed all over the place at gateway earth stations, but now not so much. For user terminals everything is pretty much feed mounted and you don't see any external waveguide.
Wow that’s a lot of experience. Yes that’s a trend for sure. UHF television transmitters are good examples of use, but now with everything streaming, I wonder how long terrestrial broadcast will last. Thanks for the comments.
Excellent presentation!
Thank you kindly!
A really clear and straightforward explanation, thanks!
(And that choke flange is such an ingenious design! It seems like it would only work perfectly at a single frequency though. The waveguides themselves can be used for a range of frequencies, do they make choke flanges for specific frequencies within the range, or are they good enough across the typical range?)
Thanks for the comment. The ones with circular features have an increasing VSWR as the frequency increases. Some choke flanges have horizontal features which eliminates that issue for the most part.
Immensely insightful, thank you so much ❤❤
Thanks so much.
This was fascinating, thank you. I'm 32 and I've spent a lot of time exploring the various long-lines towers in my area and I've never even remotely understood how waveguides worked until now. I just assumed they were like a fiber-optic pipe for radio waves, hap hazard bouncing along like a river of energy in there.
As a machinist by trade, I find it particularly fascinating the relationship of the physical dimensions and tolerances to the frequencies and efficiency of the system.
Can it be dangerous to send the wrong frequency down an incorrectly sized waveguide to ending up with current on the exterior surfaces of the waveguide?
Thanks for the comment. I believe the only thing wrong you can do is overpower it.
Thank you. This is very helpful.
Nano ohmmeter 😂
Glad it was helpful! Thanks for the comment.
o wow. jus found ur channel. very cool stuff
Thanks so much.
Thank you.
You're welcome!
excellent, I know nothing about wave guides but that helps no end. I do wonder how the ripples in the flexible concertina walls don't cause all sort of reflections, are they at 1/4 wavelength apart or something?
I don't have any experience with the flexible elliptical waveguide. I surmise that it only adds length, otherwise it would not be very useful. Thanks for the comment.
thank you very much
Thanks for the comment.
Not my speciality, but I try to understand the topic anyway. Thank you!
You're welcome. Thanks for commenting.
JJ Thompson was incredible
Indeed.
4:50, that jump to the quarter wavelength stub was jarring. I see how you were using it as a transitory, and I like how you use this as a kind of lemma to explain waveguides, but I had to rewatch it a few times to make sure I respected the explanation.
If I understand correctly, the reason we have the stub was to attenuate all signals that aren't at that frequency (or integral modes thereof) and set the junction point to 0V (via a standing wave) if they are.
Yes that’s a good way to put it.
I built a microwave plasma machine for diamond synthesis. I could never deliver enough power to the load. Now I see why. Thanks!
Thanks for the comment.
👏👏👏🔝👍
Thank you.
@@oldhackee3915 😊😊👋
Transport your mind to the world of metallic insulator and air short and it's all clear! 🙂
Glad it helped.
My lucky numbers: 75, 51, 28 & 15.
A glass rod is just a waveguide for THz RF ùwú
The math melts my brain, but i can intuitively visualize the fields in a general sense for stuff like this. But the details escape my grasp.
Sorry. Wish it would have been more helpful.
"Imagine the conducting wires as bus bars that don't actually exist" HA!
Please loose the feet and inches. Metric gets rid of the constants and makes the formulas simpler to understand.
I get it. I'm not a fan of the imperial system. However, the standard waveguide numbers were based on inches, so I was not inclined to change. Thank for the comment.
@@oldhackee3915as much as equipment parts may be imperial, how about say for just general equations, such as 14:25 having attentuation in dB/length, such situations use metric? There isn't a need to think about the length of a waveguide in metric after all, only the cross section since that is the manufacturer "standards"
I understand. To further complicate things, every waveguide drawing I ever saw was dimensioned in inches. 🤯
Geeze go back to Russia , here in America we use feet and inches because they are better
@@oldhackee3915 I'm commenting from the non-US portion of the world..
SAE is ONLY used in the US.
ALL other countries, with the exception of 1 ( some Asian country which still rejects metric, iirc ), use metric.
The SAE stuff may well be comfortable for the percentage of kids who grew-up within the US, in the SAE system,
but all the kids who failed *as a result of* the SAE system,
because the sometimes-base-12 ( inches-in-feet ) & sometimes-base-16 ( much of the rest of the SAE system is either base-8 or base-16, like ounces-in-pounds, etc ),
are not served by SAE.
Neither are all the people who never got passed/failed in the SAE system, because they were blessed by the metric system, in school.
I'm old.
I was in the Imperial system ( 10lbs water == 1 imp gallon of water ).
SAE actively-harms understanding of people trying to get the hang of things, from square-zero.
I've tried doing conceptual aircraft design, & SAE turns solving problems into nightmares.
That the US textbooks reject metric *eradicates* much potential-creativity from our current-world's population:
much more percentage of people can understand metric, than SAE, due to all the bogus fractions & odd measures.
That is like having a "tradition tax" on everybody, that everybody need pay, just because it's established.
The basic principle of "sunk costs NEVER justify current-spending", that the business world stuck to,
is correct.
We need to ditch the old archaic spellings ( I'm talking at me, here, with my more English style spellings, "colour" instead of "color", etc ),
& we need to ditch the old archaic SAE calculating,
because *both* damage the ability of much of our populations to learn stuff, for archaism's sake??
I'm deeply grateful to you for your contributing this video: these things were never understood by me, before,
& at-least I can now get the hang of the fundamental concepts..
but equations rooted in SAE .. whether in aviation-engineering, or in electrical-engineering,
they harm learning,
& therefore they are only a tradition-tax.
Taxes have their place ( one's immune-system consumes 1/10th of one's calories, one's brain 1/4, so those are "taxes",
& the benefits of both of those is well worth it, right? ),
but tradition-tax, which damages one's entire economy's innovation-*ability* .. I draw the line at that kind of thing..
Thank you for making your videos!
Please consider making a metric-equivalent for each SAE version, & label them, right in their title, as metric,
& you'll get fans from *outside* the US..
& those fans will be learning real understandings, which will help our world be more strongly innovating,
as all the makers are more strongly innovating..
Salut, Namaste, & Kaizen, eh?
_ /\ _