Circuit Envelope Simulator Question - RF Cafe Forums
Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views. It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if you would like to post something on RF Cafe's Facebook page, please do.
Below are all of the forum threads, including all the responses to the original posts.
Post subject: Circuit Envelope Simulator Question..
Unread postPosted: Fri May 21, 2004 11:55 am
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:
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.
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 ;-)
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.
Unread postPosted: Fri May 28, 2004 10:31 am
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.
More than 10,000 searchable pages indexed.