Post subject: Inductance lead effects Posted: Fri Sep
09, 2005 3:59 am
Joined: Tue Mar 15,
2005 11:43 pm
designing 3.5GHz power amplifier module, with the clip pin lead. I'm
wondering whether the inductance of the lead (especially output lead)
will significantly affect the performance?
and also due to the
substrate thickness, the lead will be bent to connect to evaluation
board (jig). So, there'll be gaps in between. I'm not sure whether it'll
affect the performance especially at 3.5GHz range?
some simulation by adding some inductance at the output. The gain is
not significantly affected, but there's some effect at output return
loss ( although not "high" ). Since so far, I only be able to do small
signal simulation, I'm worried that it'll affect power performance at
Could anybody kindly advise me how to do the "right
and accurate" simulations to observe/ predict the effects on overall
I need to prepare some anaylsis before send to fabrication.
Your advice is much appreciated.
Thanks and Regards,.
Post subject: Posted: Fri Sep 09,
2005 9:03 am
Joined: Mon Jun 27, 2005
didn't understand compleltly from your description what is a clip pin
Could you tell what is the package type?
mean that there is an air gap between one pin of yor active device to
the substrate this will certainly cause a discontinuity in the impedance
and will affect your return loss. If this occurs at the output it could
be worse, because as you may know, the output is much more dominant
in PA design.
I think that you can simulate an air-gap by measuring
the dimensions of the air-gap and add a shape(s) of transmission line(s)
with the same dimensions that has a dielectric coefficient of Er=1 (Dielectric
coefficient of air).
Please provide the information above so
I can help you more.