return loss is (almost always) a positive number. If one insists on negative numbers, just call it s11 (or s22). In essence the same property, but negative.
Op 4-10-2019 om 17:20 schreef Ron Spencer via Groups.Io:
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I read a recent post that said that, among hams, its become the consensus that return loss is a negative number. I respectfully disagree.
Regarding return loss, I understand some think its a negative number, some a positive. I am in the later camp. Why? When I was a young engineer I had the great fortune, in the early 1980s, to work for HP. Arguably the premier test and measurement company of its time. And equally arguably a leading if not THE leading microwave and rf company.
As new sales people, we were sent to 3, 3 week training sessions to learn the technology and the products so we might interact with our engineering customers in a technically sound way.
One thing HP taught, as I've said in a much earlier post, was that return loss was always a positive number. As someone on this list pointed out, negative loss is gain. And we KNOW that no return loss measurement, of a passive device, can exhibit gain.
With respect, there is no gray area here. Return loss, is always a positive (or, perhaps better said, a non- signed) number.
Even if you are at a hobby level of involvement, why not use the proper, and correct, terminology? If you're a private pilot, you are expected/ required to use the proper terminology. Same if you are an amateur road racer. Or "fill in your favorite" hobby.
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