zin & zout for rf amp (mistakes made in my last post)

[expytronicrf]

hi all, thanks for reading again

much shorter and I think more correct version, I think :

i want to ask if somone can please actually measure the input and output impedances of this amp' in above link (no spice models please). it would be used at 28mhz & power in of 20mw. for the entirely professional approach this obviously needs a Large Signal Vector Analyser. its a simple & question but, one of you may have access to facilities to do this. Is there anyone on here or anywhere that could please. if you have any other techniques to measure like a return loss bridge then you you try that and see hat you get for zin & zout please. i accept this last method isnt the full professional treatment but, its just to get a rough estimate.


any help here appreciated & thanks.


i posted this before but, i think i rambled on too much. i also made a stupid mistake in my previous post by mentioning putting an attenuator in front of a small signal vector network analyser port. i should have said to do this at the output mesurement port of a return loss bridge to do a rough estimate. so anyway i apologise for my silly mistake.

& just one last thing how do i make the image file actually appear in the post rather than just its link to open it.

 

[Tomsin yin]

u can have a try by using VNA!

 

[D.A.(Tony)Stewart]

You can drive any simulator with a series resistance of choice like 50R and then adjust bias until input is 50% or in other words R in= 50R. For hFE=200, @5V Rb= 9~10k and ditto with the Load.

Thus for Rb=9.5k Zin = 50 Ohms and Zout=200 Ohms with same load, Av=350

Examine results here