Oops,
This was not meant to be sent to the list, but privately to someone who
emailed me on the subject.
Anyway, I stand by what I said
1) Return loss should be positive for passive components.
2) I have no desire to try to convince others to my way of thinking.
Dave
On Fri, 4 Oct 2019 at 20:55, Dr. David Kirkby <
drkirkby@...> wrote:
Yes, I am G8WRB.
The problem is return loss is *often* used as a negative number in
professional academic publications. This one from an IEEE, has a
particularly amusing title;
Low-Return-Loss Printed Log-Periodic Dipole Antenna
Published in
IEEE Antennas and Wireless Propagation Letters
<>
( Volume: 13 )
Page(s)
503 - 506
ISSN Information
INSPEC Accession Number
14195004
DOI
10.1109/LAWP.2014.2310057 <>
Publisher:
IEEE
Sponsored by
IEEE Antennas and Propagation Society <>
and another, not published by the IEEE,
and another
As such, whilst I will continue to use a positive for all passive and most
active components, I really have no appetite for changing the mind of
others.
On Fri, 4 Oct 2019 at 20:26, Reinier Gerritsen <r.gerritsen@...>
wrote:
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:
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.
Sent using
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
Telephone 01621-680100./ +44 1621 680100
Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT,
United Kingdom
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
Telephone 01621-680100./ +44 1621 680100
Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom
