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Old January 21st 09, 11:31 PM posted to rec.radio.amateur.antenna
Frank[_9_] Frank[_9_] is offline
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First recorded activity by RadioBanter: Dec 2008
Posts: 23
Default Antenna System VSWR/Return Loss Calculation

wrote in message
...
I have a question about how to calculate VSWR/ReturnLoss of a hybrid
antenna/feed line sysem which include bottom jumper, pressure window,
wave guide, upper jumper and antenna? I list the parameters of all the
components as bellow for an actual instance:
VSWR InsertionLoss
Antenna 1.06
Antenna Radome 1.01 0.4
Top Jumper 1.03 0.09
Waveguide 1.06 2.36
Pressure Window 1.01
Bottom Jumper 1.03 0.09

Could somebody help me get the ReturnLoss/VSWR at the end of Bottom
Jumper for the entire system? Thanks.


You need to fully characterize each component with 2 port S parameters.
You can then determine the cascaded parameters by the use of T
parameters. You need a vector network analyzer to acomplish
this. The procedure is described in HP's application note AN-154
"S parameter Design", available at:
http://www.hpmemory.org/ressources/resrc_an_01.htm#

Regards,

Frank