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Issue with Envelope analysis

AparnaG
Hi,

I am simulating the I/Q upconversion using port through envelope analysis.
The I input pwl file has samples of a cosine of frequency=5MHz and timestep=0.00125us.
The Q input pwl file has samples of value=0 and timestep=0.00125us.

The original I, Q pwl files have data upto 2ms. I have attached the I, Q pwl files having data upto 1us, as the size of original files are much bigger.
The setup has a port of 100ohms and a resistor of 100ohms connected in series. By theory, the output spectrum of the first harmonic is expected to have 2 sidebands at 5MHz and no component at carrier. But in my envelope analysis simulations (envelope harmonic balance and shooting), I observe a significant component at the carrier. Whereas in fast envelope, the component at the carrier is not very significant. The plots are attached. The relevant portions of the netlists in all 3 cases are included at the end.

Could you please help me in debugging this issue?

Thanks & Regards,
Aparna

The plotting options used:
Description - Main Channel Power
Reference resistor - 100ohms
Start : 0 Stop : 2m
Strobe period : 1m/65536
Window Size : 65536
Repetitions : 2
Resolution : 1k
Window : Cosine4


ICFB version - 6.1.4-64b.500.10
Spectre version - 12.1.0.272


*************************************Normal Envelope(HB)******************************

V0 (gnd1 0) vsource dc=0 type=dc
PORT0 (net1 gnd1) port r=100 type=sine freq=frf ampl=1 pwldbm=plo \
        pwlfilter=none rolloff=0.1 pwlbandwidth=20M iqmodfiles=[ \
        "/data/ee11s027/desk/mod_data_acpr/cosine5MHz_2ms_highres" \
        "/data/ee11s027/desk/mod_data_acpr/zero_2ms_highres" ]
R0 (net1 gnd1) resistor r=100
simulatorOptions options reltol=1e-7 vabstol=1e-10 iabstol=1e-16 temp=27 \
    tnom=27 scalem=1.0 scale=1.0 gmin=1e-12 rforce=1 maxnotes=5 maxwarns=5 \
    digits=5 cols=80 pivrel=1e-3 sensfile="../psf/sens.output" \
    checklimitdest=psf 
envlp  envlp  flexbalance=yes  stop=2m  oversample=[1]  fund=frf
+      harms=20  stepperiod=0.005u  fixstepsize=yes  errpreset=moderate
+      fastmode=off  tstab=0.2m  annotate=status
modelParameter info what=models where=rawfile
element info what=inst where=rawfile
outputParameter info what=output where=rawfile
designParamVals info what=parameters where=rawfile
primitives info what=primitives where=rawfile
subckts info what=subckts  where=rawfile
saveOptions options save=allpub



*************************************Fast Envelope(level-1)******************************


V0 (gnd1 0) vsource dc=0 type=dc
PORT0 (net1 gnd1) port r=100 type=sine freq=frf ampl=1 pwldbm=plo \
        pwlfilter=none rolloff=0.1 pwlbandwidth=20M iqmodfiles=[ \
        "/data/ee11s027/desk/mod_data_acpr/cosine5MHz_2ms_highres" \
        "/data/ee11s027/desk/mod_data_acpr/zero_2ms_highres" ]
R0 (net1 gnd1) resistor r=100
simulatorOptions options reltol=1e-7 vabstol=1e-10 iabstol=1e-16 temp=27 \
    tnom=27 scalem=1.0 scale=1.0 gmin=1e-12 rforce=1 maxnotes=5 maxwarns=5 \
    digits=5 cols=80 pivrel=1e-3 sensfile="../psf/sens.output" \
    checklimitdest=psf 
envlp  envlp  flexbalance=yes  stop=2m  oversample=[1]  fund=frf
+      harms=20  stepperiod=0.005u  fixstepsize=yes  errpreset=moderate
+      fastmode=level1  srci=["PORT0"]  srcq=["PORT0"]  output=["net1"
+      "gnd1"]  tstab=0.2m  annotate=status
modelParameter info what=models where=rawfile
element info what=inst where=rawfile
outputParameter info what=output where=rawfile
designParamVals info what=parameters where=rawfile
primitives info what=primitives where=rawfile
subckts info what=subckts  where=rawfile
saveOptions options save=allpub



*************************************Shooting******************************


V0 (gnd1 0) vsource dc=0 type=dc
PORT0 (net1 gnd1) port r=100 type=sine freq=frf ampl=1 pwldbm=plo \
        pwlfilter=none rolloff=0.1 pwlbandwidth=20M iqmodfiles=[ \
        "/data/ee11s027/desk/mod_data_acpr/cosine5MHz_2ms_highres" \
        "/data/ee11s027/desk/mod_data_acpr/zero_2ms_highres" ]
R0 (net1 gnd1) resistor r=100
simulatorOptions options reltol=1e-7 vabstol=1e-10 iabstol=1e-16 temp=27 \
    tnom=27 scalem=1.0 scale=1.0 gmin=1e-12 rforce=1 maxnotes=5 maxwarns=5 \
    digits=5 cols=80 pivrel=1e-3 sensfile="../psf/sens.output" \
    checklimitdest=psf 
envlp  envlp  stop=2m  fund=frf  harms=20  stepperiod=0.005u
+      fixstepsize=yes  errpreset=moderate  tstab=0.2m  annotate=status
modelParameter info what=models where=rawfile
element info what=inst where=rawfile
outputParameter info what=output where=rawfile
designParamVals info what=parameters where=rawfile
primitives info what=primitives where=rawfile
subckts info what=subckts  where=rawfile
saveOptions options save=allpub
IQ_pwl_files_plots.zip

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