Products > Test Equipment
Smitih Charts, still relevant in 2024?
<< < (9/9)
Joel_Dunsmore:
The smith chart is just another representation of reflection, but it has the advantage of telling you if the impedance mismatch is following a series or shunt reactive element and whether it is inductive or capacitive.  You example of the lines being 50 -j7 is a good example: if we look at this on the Smith chat, and over a broader range, we can tell whether it is a capacitive or inductive discontinuity that is giving you the reactive portion (for an example like that one, you likely have a connector discontinuity at the input as the loss of coax is low so it's imaginary part is small if there are no other discontinuities).  Same at the far end; measured over a broader range of frequencies will tell you if it is following a series/shunt inductive/capacitive trajectory at a glance, and you can then quickly deduce the best matching network.
Joel_Dunsmore:
Depends on the purpose of the matching.  I had a design of amplifier which had too much low-end gain and was only conditionally stable;  A little lossy matching inter-stage made it unconditionally stable and the matching was used to flatten the amplitude response (better matching at high frequency).
joeqsmith:
Welcome back Mr Dunsmore.
coppercone2:
the proper engineering methodology is

"does the extra loss of the matching stage bring the loss budget to an unacceptable level?"

I think that is how you wanna think about it when you are problem solving for someone to develop a engineering solution. There might be something else that can be changed to reduce loss or increase power to allow for resistance to be used. For instance, a slightly better cable. Some people will say thats OK. It might even make it someone elses problem if they agree to your spec.

of course if your lazy and use resistance by default, someone more diligent in research and development might steal your customers if the price is right
Navigation
Message Index
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod