Understanding VSWR and Return Loss

Beautifully made presentation/explanation. 5/5!

I just found the Gold mine, and the fact it comes from my favorite Test&Measurement company is icing on the cake.

Very informative. Thanks.

What an excellent video, more like this please!

The terminology of Return Loss for me is very counterintuitive. Instead of difference Forward - Return power I would rather use the ratio of Return / Forward. As we call it Loss how can we strive to maximize the number? Loss should be a low number, or low percentage.

I like this comment and it is spot on. The pacing of the speech and clarity videos is just right in an area of Radio Frequency engineering that is not easy to grasp. No wonder Rhode and Schwartz make the best analysers in the industry. I wish I could afford to buy one.

Excellent video, how you got percentage of return loss ?

so nice！

Coming from an avionics background, this video was beneficial since it was only briefly mentioned, and it was more about hooking equipment up, and it will measure it for you. This will definitely be used to help teach others what VSWR is. Thank you.

Absolutly great presentation!!! Thank you!

Will the IL,RL characteristic value change according to the reference input to the POGO connector?
For example, Will the IL change according referance input 0dBm Vsersus 35dBm?

Very helpful!

this helped me through HF/RF Engineering thanks

Thank you.
You filled a gap in my knowledge.
I repeatedly ran too much power for a GC MS and had a foldback circuit shut the power down. The field engineers could not explain this to me. It did not help that I had no meter to let me know I was approaching the power limit.
Thanks again. N0QFT

Thanks for the clear explanation!!

SUPERB. What a great explanation.

There is an ambiguity, in that the presentation can leave the impression that reflected power gets back into the source and destroys the equipment. This is of course not true. It would be useful to link the rising voltage in the voltage charts to the damage caused to the source device as the explanation of the danger of high SWR. The alternate case of course is very high currents.

I'd like to make three important points, all of which can be easily proven as fact:

1.) Reflected power is absolutely NOT what damages a PA device or stage. It is the mismatch in optimum impedance at the output port, regardless of standing waves or reflected power on the feedline some distance away from the PA stage.

2.) It is quite possible to have a very high percentage, actually nearly 100%, of transmitter power delivered to a load even with a very high "reflected power" or VSWR.

3.) Many antenna systems, as well as PA matching, splitting, and combining systems, intentionally operate with fairly high standing waves. Collinear antennas, like VHF/UHF multiple bay arrays, commonly use mismatched transmission lines in harnesses to split power and match the multiple elements to the feed impedance. These harnesses and cables often operate well over 2:1 VSWR in the feed cables with negligible loss.

Thanks, this is so pleasant to learn from.

Excellent presentation on understanding the Return loss and importance of VSWR.

great, thank so much for that knowledge you provided

Wiki
From a certain perspective 'Return Loss' is a misnomer. The usual function of a transmission line is to convey power from a source to a load with minimal loss. If a transmission line is correctly matched to a load, the reflected power will be zero, no power will be lost due to reflection, and 'Return Loss' will be infinite. Conversely if the line is terminated in an open circuit, the reflected power will be equal to the incident power; all of the incident power will be lost in the sense that none of it will be transferred to a load, and RL will be zero. Thus the numerical values of RL tend in the opposite sense to that expected of a 'loss'.

Thank you! Such a beautifully explained video!

very nice presentation

Very well presented.

thank you so much

Just getting into amateur radio, this is very helpful.

To the point and very informative. Thanks a lot for the share!

Sir, your idea of vswr is different from what some materials say. They say vswr is ratio of voltage max at the peak and voltage minimum at the trough/bottom. Your explanation of it in the graph appears different. Also, textbooks don't mention that impedance matching means load impedance is the complex conjugate of the source or line impedance. They say it should be exact match. Could you please clarify. Thanks in advance.

I am now 66 retired and way back in 1985, I took a 9 month course of Microwave electronics at Microwave Training Institute in Mountain View, California, a school privately owned by Alan Scott. Learned the basics, Operation of Klystrons, Reflex Klystrons, low frequency circuits, microwave circuits and laboratory experiments using microwave instrumentation and USE OF THE SMITH CHART. This video VISUALIZATIONS are awesome and I HAD A HARD TIME visualizing what those PHYSICISTS and Working Engineers teaching us those concepts, I finished the course knowing all these magic microwave skills and went to work at a few companies building microstrip gallium arsenide microwave amplifiers 4 - 18 Ghz at the time tuning and cascading them, with a lot of microscope work. Thank You for MAKING this VIDEO, the time and dedication you have explained these concepts in simple clear manner. God Bless You.

Excellent video sir..... it helped me understand the thing. Thanks a lot !!!

amazing explanation thanks sir

Excellent, Excellent, excellent video! THANK YOU!! I subscribed...

One of the best lectures I have ever come across. Thank you so much sir!

that was really helpful. Thanks for the content.

Thank you

I'm trying to troubleshoot a high voltage power transmitter with valuable freq.. Problem is an over current fault which shuts down the transmitter. This video is helpful, TY

Paul..... in my 76 years I have seen a "FEW" VIDEOS. THIS ONE IS BY FAR THE BEST and clearest I have seen. on this subject. Coming from your company, i am not surprised, Rhode & Schwartz are well known for the top quality of their instruments. Thank you for taking the time and effort in producing this. Please rest assured that it is VERY MUCH appreciated. IGNORE the dislikes... Even if God himself would have done this video... he too would get dislikes... and probably more of 'em !
Albert EI7II.

I didn't know actor James Woods was into antenna efficiency! :)

A clear and good presentation. Thank you.

most understandable vide I saw on that topic. great job

Another fantastic video, summarising what my lecturer failed to convey in 2 hours in 10 mins! Love this series!

Wow superb video! Thanks!

omg this video was so informative; thank you a tonne

That graph at min 5 was all that i was needing.