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Simulators >> RF Simulators >> What is the meaning of the Harmonic number in PAC mixer simulations
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Message started by DoYouLinux on Mar 19^th, 2009, 4:22am

Title: What is the meaning of the Harmonic number in PAC mixer simulations
Post by DoYouLinux on Mar 19^th, 2009, 4:22am

Hi all,

I am reading a document indicating how to simulate mixers in Cadence. In the direct plot form of the PAC, in the output harmonic windows, as shown in the attached picture, there are harmonics number in one column and frequency in the other column. I really don't know the meaning of the number in the left column. In this example, the LO frequency is 5 GHz and the RF is 5.001 GHz. I think "0" means the RF frequency, "-1" means the mixed-down product (5.001 - 5), "1" is the mixed-up product (5.001+5), but I don't know about the "2" and "-2". I actually would like to know how the number in the left column related to the frequency in the right column.

Could someone suggest me please ??? ;)

Thanks a lot,

DYL

Title: Re: What is the meaning of the Harmonic number in PAC mixer simulations
Post by Frank Wiedmann on Mar 19^th, 2009, 5:08am

Those frequencies are the mixing products of the RF frequency with the LO harmonics: f=|f_RF+n×f_LO|

Title: Re: What is the meaning of the Harmonic number in PAC mixer simulations
Post by DoYouLinux on Mar 20^th, 2009, 4:01am

Oh, I see now ;D Thank you very much Frank 8-)

DYL

Title: Re: What is the meaning of the Harmonic number in PAC mixer simulations
Post by Andrew Beckett on Mar 22^nd, 2009, 11:03pm

With PAC, you specify an input frequency (or commonly a sweep of input frequency) in the analysis. You also specify the maximum number of sidebands you want the analysis to compute.

The simulator will then produce outputs at F_in+k*F_pss where k is the "harmonic" number (I think it should really be called sideband, but that's the way it is), and F_pss is the fundamental for the PSS analysis. So -2 and +2 are the input frequency shifted by +/- 2 times the PSS fundamental.

Regards,

Andrew.