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Modeling >> Behavioral Models >> Ptomely-Matlab Interface
https://designers-guide.org/forum/YaBB.pl?num=1249782328

Message started by memomemomemo on Aug 8^th, 2009, 6:45pm

Title: Ptomely-Matlab Interface
Post by memomemomemo on Aug 8^th, 2009, 6:45pm

Hi !

I am modeling a high frequency phased array in Ptomely.

However I have no idea how to model the antenna array.
Should I model the "antenna array+channel" in the matlab?
After that, I wonder if Ptomely will allow me put a matlab black box inside the system.

What is the interface between ADS and Matlab? I know matlab codes can give an output text for Ptomely to use for modulation purposes..

Or should I try option 2? Designing the whole system in Simulink using baseband envelope? then modeling the channel and integrating it in the system may be simply, but I can't replace the circuits in transceiver instead of using behavioral models.

pancho_hideboo! I know you have a big depth of knowledge. Would you be able to help me with this problem? I appreciate your help!

Wishing you all a nice weekend!
Mehmet

Title: Re: Ptomely-Matlab Interface
Post by Sumit Adhikari on Aug 14^th, 2009, 1:49am

Berkeley Ptolemy has a matlab interface. Please search Matlab in right pane of your Ptolemy.
Regards,
Sumit

Title: Re: Ptomely-Matlab Interface
Post by pancho_hideboo on Nov 3^rd, 2009, 4:23am

memomemomemo wrote on Aug 8^th, 2009, 6:45pm:

I am modeling a high frequency phased array in Ptomely.
However I have no idea how to model the antenna array.
Should I model the "antenna array+channel" in the matlab?

I recommend you to use MATLAB.

memomemomemo wrote on Aug 8^th, 2009, 6:45pm:

After that, I wonder if Ptomely will allow me put a matlab black box inside the system.

Yes, you can do.

memomemomemo wrote on Aug 8^th, 2009, 6:45pm:

What is the interface between ADS and Matlab? I know matlab codes can give an output text for Ptomely to use for modulation purposes..

Ability of importing of MATLAB functions are provided as standard menu in Agilent ADS.
http://edocs.soco.agilent.com/display/ads2009/MATLAB+Cosimulation+Introduction

memomemomemo wrote on Aug 8^th, 2009, 6:45pm:

Or should I try option 2? Designing the whole system in Simulink using baseband envelope?

MATLAB is different from Simulink.
Simulink is alternative solution for Agilent Ptolemy. But there is no alternative solution for MATLAB in Agilent ADS.

However I recommend you to use Simulink not Ptolemy since we can't expect any progress in Agilent Ptolemy any more.
Only one benefit of Ptolemy is it's ability of post processing, here you can use same usemodel for Analog/RF domain.
But Simulink is superior than Ptolemy regarding performance as simulator.

memomemomemo wrote on Aug 8^th, 2009, 6:45pm:

then modeling the channel and integrating it in the system may be simply,
but I can't replace the circuits in transceiver instead of using behavioral models.

I can't understand what you mean.
There is no difference between Simulink simulation and Ptolemy simulation.
See http://www.designers-guide.org/Forum/YaBB.pl?num=1238242506/1#1

Title: Re: Ptomely-Matlab Interface
Post by memomemomemo on Nov 3^rd, 2009, 11:31pm

Thank you pancho,

I am using simulink to model the system.

I have some other questions. I am having difficult since I am new in simulink. I have a lot of real circuit data (s2p file for LNA, mixer , PA etc) and I need to model this radar system with these files.
So as you guess I am using the RF blockset.

A guy in a company told me that I can not use simulink at 60GHz or 77GHz because of the sampling. Why is it? Is it because at baseband, that means a lot of samples? I had no difficulty to do it so far but I have doubts that I am doing something wrong.

Such as I started putting a channel measured at 60GHz spectrum as a RF block. I am attaching the jpeg file which will give you an idea.

So is it right modeling? How come can use a rf blockset at passband?
Or is it possible to integrate the circuit s2p models like this in the model?

thanks a lot!
:exclamation

Title: Re: Ptomely-Matlab Interface
Post by pancho_hideboo on Nov 4^th, 2009, 7:28am

Create another thread.

memomemomemo wrote on Nov 3^rd, 2009, 11:31pm:

I am having difficult since I am new in simulink.

Basically there is no difference between Ptolemy and Simulink if you can understand concept of equivalent lowpass model for RF bandpass system very correctly.
See http://www.designers-guide.org/Forum/YaBB.pl?num=1245687123

Compared to Ptolemy, Simulink have "Frame-based sampling mode" in addition to "Sample-based sampling mode".
On the other hand, Ptolemy have only "Sample-based sampling mode".

memomemomemo wrote on Nov 3^rd, 2009, 11:31pm:

A guy in a company told me that I can not use simulink at 60GHz or 77GHz because of the sampling.
Why is it?

If your system is not bandpass system,
it is almost impossible to simulate since we can't use equivalent lowpass model or equivalent baseband model.
This is true for both Ptolemy and Simulink.

memomemomemo wrote on Nov 3^rd, 2009, 11:31pm:

Is it because at baseband, that means a lot of samples?
I had no difficulty to do it so far but I have doubts that I am doing something wrong.

I can't understand what you mean. Which do you mean "true baseband" or "equivalent baseband" ?

memomemomemo wrote on Nov 3^rd, 2009, 11:31pm:

So is it right modeling?

Show me "signal attributes" of each node, e.g. signal type, sampling rate, etc. You can show them easily in Simulink.
See http://www.designers-guide.org/Forum/YaBB.pl?num=1233929450

memomemomemo wrote on Nov 3^rd, 2009, 11:31pm:

How come can use a rf blockset at passband?
Or is it possible to integrate the circuit s2p models like this in the model?

I can't understand what you mean.
Describe with correct terminologies.

Equivalent lowpass model is not used in the following.
See http://www.designers-guide.org/Forum/YaBB.pl?num=1245687123

You have to make clear followings.
- True Baseband Signal
- Representation of RF Bandpass Signal as Equivalent Baseband Signal
- Representation of RF Bandpass Signal as True RF Bandpass Signal

About phase noise of RF Bandpass Signal, it is impossible to treat it as "Representation of RF Bandpass Signal as True RF Bandpass Signal".

It might be impossible to treat "s2p" file in "True RF Bandpass Signal" as far as you use the following "RF Blockset".
RF Blockset>Physical>Input/Output Ports>Input Port
RF Blockset>Physical>Input/Output Ports>Output Port
RF Blockset>Physical>Black Box Elements>General Passive Network

Instead, create real coefficients FIR model to express S21 as true RF Bandpass model.

Ptolemy can treat "s2p" in both "Equivalent Baseband Signal" and "True RF Bandpass Signal" seamlessly.
Ptolemy calculate complex coefficietns FIR model for former case and real coefficients FIR model for latter case.

Title: Re: Ptomely-Matlab Interface
Post by memomemomemo on Nov 5^th, 2009, 10:27am

Hi Pancho,

I am very confused with the RFBlockset. Should the input to the input port of rfblockset be a baseband signal? In my simulation, I was giving a passband signal to the rfblockset. then After the rfblockset , I was down-mixing it to get the baseband signal.

Would you give an email of yours, so I can send my simulink file to you?

Title: Re: Ptomely-Matlab Interface
Post by pancho_hideboo on Nov 8^th, 2009, 1:17am

memomemomemo wrote on Nov 5^th, 2009, 10:27am:

Would you give an email of yours, so I can send my simulink file to you?

I'm not kind and patient enough.

You had better expect that other people who is very kind and patient could help you.