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Simulators >> RF Simulators >> PSS and PSP Analysis for mixer
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Message started by mreja on Feb 22^nd, 2004, 3:18pm

Title: PSS and PSP Analysis for mixer
Post by mreja on Feb 22^nd, 2004, 3:18pm

Feb 22, 2003.

Hi Everyone,

For simulating mixer with SpectreRF simulator, How I can set up the PSP analysis. For example, LO signal at 1.8GHz and RF signal at 1.9GHz and obviously IF=100MHz. In PSP analysis, what should I do for the following:

1. Sweeptype: Relative or Absolute ?

2. Frequency sweep range for Relative or Absolute.

3. Select ports: port1 (mixer input port)
- Port 2 (IF output port)
- How do I choose the LO port. Is it Auxiliary port?.

4. what will be harmonics no. for these ports both for Relative or Absolut.

With above example (RF=1.9GHz and LO=1.8GHZ, Fundamental frequency=100MHZ and IF=100MHz), would you please someone tell me the PSP analysis setup both for Relative or Absolute sweeptype.

Thank you very much.

Reja

Title: Re: PSS and PSP Analysis for mixer
Post by Andrew Beckett on Mar 5^th, 2004, 1:47am

PSP is a little complicated to set up - it's got rather clearer
in the UI from IC5032 onwards (it now allows you to select
from a list of frequencies, for example).

Here's what I'd expect you to set up:

1. RF signal as DC - no sine wave input here (you can
treat it as small signal, unless you're trying to measure the
noise/s-parameters in the presence of a blocker, or a
signal driving the mixer into compression).
2. LO as large, of course. This means that your PSS
frequency will be the LO frequency, and hence 1.8GHz.
3. I always recommend using sweepmode "relative" in
PSP, because it's easier to understand. The frequency
of each port is then determined by f+k*PSSfund where
f is the spot frequency, or sweep range of the sweep.

So in this case, you'd have port 1 as the RF port,
port 2 as the IF port. No need to have the LO port
mentioned at all (unless you're trying to find the
s-parameters between IF and LO or RF and LO, which
I doubt).

Then have either:

frequency sweep around 1.9GHz (or a spot frequency)
Input port harmonic as 0 (no shift)
Output port harmonic as -1 (shifted down by 1.8GHz)

or

frequency sweep around 100MHz (i.e. output frequency)
Input port harmonic as 1 (to get to input frequency)
Output port harmonic as 0.

Absolute mode is very confusing, because the frequency
sweep is always used for the first port in the mode, but
the remaining ports are shifted relative to the input port.
Relative mode is where the "harmonic" number specifies
the amount of PSSfund shifts on that part relative to
the frequency sweep.

Hopefully that will clarify things a bit?

Regards,

Andrew.