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Circuit Envelope Simulator Question - RF Cafe Forums
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paolo Post subject: Circuit Envelope Simulator Question.. Unread
postPosted: Fri May 21, 2004 11:55 am
hello everyone, I use
ADS to simulate a PA (modeled by a .p2d file) feedforward linearizer.
Anyone knows if in circuit envelope simulations the group delay of the
amplifier is actually evaluated?or should i include it as an external
delay element? tnx in advance :wink:
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Itay
Post subject: Unread postPosted: Sat May 22, 2004 2:35 am
I think you may add the group delay option in the HB simulation
engine. When you simulate a linearizer you use HB or LSSP engines to
view the non-linear S-parameter results. There should be an option to
view the group delay of the circuit as you do it with linear simulation.
I should also check this option myself. If not, then try to use the
S-parameter engine only and check the group delay option.
BTW
Feedforward is not trendy nowadays, there are Pre-distortion techniques
which are more popular. If you need information I will be keen to help
you.
Good luck, Itay :mrgreen:
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paolo Post subject: Unread postPosted: Wed May 26, 2004 5:03
am
tnx for the reply.. :) i need to use envelope simulation
to see the behaviour of the linearizer when fed with complex signals,
in the controller there is no any group delay option. as long as i remember
it is peculiar of s-parameter controller, and is used to store in a
variable called "delay" the group delay calculated from s-parameter
phase. anyway i am almost sure it is not evaluated in simulation
and so am using an external delay element. if someone has a final ansewer
on the subject i am listening ;-)
ciao
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Itay Post subject: Unread postPosted: Thu May 27, 2004
3:13 pm
Are you using the Ptolmy tool for envelope simulation
or another tool?
You said that you use an external element for
delay, Are you using it as a constant reference delay at the input and
by that derive the the delay that your system contributes?
There
must be a delay option that as you said is calculated from the delay
of the S-parameters: delta phase/frequency, and from that the group
delay is derived. I used it myself not long ago to find a group delay
of a filter.
Thanks, Itay
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paolo
Post subject: Unread postPosted: Fri May 28, 2004 10:31 am
hi,
i am using envelope inside the RF/Analog simulator,
not ptolemy.
i introduced a delay element after the amplifier
to simulate the effect of the group delay, because i didn't see the
effect of the group delay on the previous simulations results.
i couldn't find any option related to group delay in envelope controller,
i looked in the hidden parameters (the ones in the display tab) but
found nothing.
tnx,
paolo
Posted 11/12/2012
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