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Chapter 8: Large Signal Periodic AC, Transfer Function, and Noise Analyses
Phase Noise and Buffer Chains
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Maximum Krylov Iterations
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Actual Krylov Iterations taken
SNAC Example
The following example is shipped with the HSPICE RF distribution as
mix_snac.sp and is available in directory:
$installdir/demo/hspicerf/examples.
* Test SNAC: ideal I,Q mixer -rrd
.OPTIONS PROBE
.OPTIONS POST=2
$.OPTIONS snmaxiter=100
.OPTIONS SNACCURACY=5
vlo lo 0 1.0 cos(1.0 0.5 1g) $ Periodic, Large-Signal SN Input
rlo lo 0 1.0
rrf rf 0 1.0 $ Noise source
rrf1 rf1 rf 1.0 $ Noise source
g1 0 if cur='1.0*v(lo)*v(rf)' $ mixer element
c1 0 if q='1.0e-9*v(lo)*v(rf)' $ mixer element
rout if ifg 1.0
vctrl ifg 0 0.0
h1 out 0 vctrl 1.0
rh1 out 0 1.0
vrf rf1 0 snac .001 24.0 $ Small signal for SNAC with 1-tone
SN Input
.sn tones=1.0g nharms=3
.snac lin 1 0.8g 0.8g
.print sn v(rf1) v(lo) v(out)
.print snfd v(rf1) v(lo) v(out)
.print snac v(rf1) v(lo) v(out)
.measure snac vout1 find v(out)[1,-1] at=0.8g
.measure snac vout2 find v(out)[0,1] at=0.8g
.measure snac vout3 find v(out)[1,1] at=0.8g
.measure sn vlo1 find v(lo) at=0.5n
.measure sn vlo2 find v(lo) at=1n
.measure snfd vlo3 find v(lo)[1] at=1
.end
Phase Noise and Buffer Chains
Phase noise is specific to oscillators. However, for buffer chains you can do
periodic noise analysis. Phase noise that may be contributed by buffer,
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HSPICE® User Guide: RF Analysis
E-2010.12