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Simulators >> Circuit Simulators >> How to simply define a multiple-tone signal ???
https://designers-guide.org/forum/YaBB.pl?num=1149833218

Message started by cowell on Jun 8^th, 2006, 11:06pm

Title: How to simply define a multiple-tone signal ???
Post by cowell on Jun 8^th, 2006, 11:06pm

Hi,
i want to ask is it possible to SIMPLY realize defining a multiple-tone(about 130 tones) signal in Cadence?
You know, it would be a very heavy load if just arrange so many signal voltages in the circuits.
Is there any structively suggestion?
thx in advance. :-[

Title: Re: How to simply define a multiple-tone signal ??
Post by Ken Kundert on Jun 9^th, 2006, 10:53pm

Using Verilog-A would be a good approach. Alternatively, you could use 130 current sources into a resistor.

-Ken

Title: Re: How to simply define a multiple-tone signal ??
Post by simon2 on Sep 23^rd, 2007, 5:45am

Hi cowell,
I guess you already have a solution - so this is for the benefit of others reading this post "after-the-fact":

If you can create the signal (say in excel) then you can take the output signal as a set of time-voltage (or current) paired points and place them into a pwl source'sdefinition. In spectre this can be done quite easily with a pwlfile source pointing to the above pairs correctly formatted csv file which can easily be manipulated in a text editor.

I have in the past done something similar using captured data from real-world instruments (such as a DSO) and used spice as a DSP tool.

You could also generate your "signal" in an arbitary waveform generator or capture it from a test instrument.

You did not say what the application was - if it is something like an OFDM signal, you may find that you do better by choosing a low number (say four or eight) strategically placed tones to represent the signal, then work with them. Doing so, should speed up your simulations as the simulator does not have to converge at so many different data points needed to define the input signal.

Cheers,
SimonH.