The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Simulators >> RF Simulators >> Question on Sampled PAC
https://designers-guide.org/forum/YaBB.pl?num=1577233223

Message started by iVenky on Dec 24^th, 2019, 4:20pm

Title: Question on Sampled PAC
Post by iVenky on Dec 24^th, 2019, 4:20pm

Hi,

I am wondering what the sampled PAC does exactly.

Let's say I have an LPTV system H(jw,t)=ΣH_k(jw) e^jkw_st where w_s = 2Π/Ts where 'Ts' is the periodicity of the system & 'k' is an integer from -∞ to -∞.
Here H_k(jw) are the harmonic transfer functions.

Let's say we have an input x(t)=e^jw_int to the system H(jw,t) and whose output is y(t) which has the frequency translated input x(t) scaled by the harmonic transfer functions.

What does the sampled PAC at a time 't0' actually measure? I can understand PAC voltage gain, which looks at the gain frequency translated output magnitude to input magnitude. On the other hand, what does sampled PAC voltage gain do?

Thanks in advance and Happy Holidays :)

Title: Re: Question on Sampled PAC
Post by Frank Wiedmann on Jan 8^th, 2020, 7:54am

Sampled PAC gives you the signal that you would see at the output of an ideal sampler that is running at the frequency of the PSS analysis (see https://support.cadence.com/apex/techpubDocViewerPage?&path=spectreRFTheory/spectreRFTheory19.1/chap2.html#pgfId-1042551). For an explanation of ideal sampling, you can take a look at Ken's paper https://designers-guide.org/analysis/sc-filters.pdf. When he wrote it, the sampled PAC and PXF analyses had not yet been implemented in SpectreRF, so he used an ideal sample-and-hold written in Verilog-A.