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 Issue with Envelope analysis 

Last post Sat, Mar 8 2014 9:42 PM by AparnaG. 0 replies.
Started by AparnaG 08 Mar 2014 09:42 PM. Topic has 0 replies and 747 views
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  • Sat, Mar 8 2014 9:42 PM

    • AparnaG
    • Not Ranked
    • Joined on Fri, Jul 29 2011
    • Posts 1
    • Points 5
    Issue with Envelope analysis Reply
    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
    • Post Points: 5
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Started by AparnaG at 08 Mar 2014 09:42 PM. Topic has 0 replies.