Passive switching mixer volatge conversion gain calculation and its varition with frequency

Hi Andrew,

Sorry for not specifying the problem correctly. I am not getting correct gain (loss) out of the passive mixer . My test bench looks like following:

c1=500fF

Conversion gain was calculated using pss+swept pac. For pss analysis , # of harmonics set to 0 . Port0 is dc type (based Spectre RF simulation manual)  . In Swept pac # of sidebands  was set to 2. The input.scs looks like following:

// Library name: MIXER_CHARACTERIZATION
// Cell name: RX_MIXER_FUNDAMENTAL_RZ_MOS_PSF_PXF
// View name: schematic
PORT0 (RF 0) port r=50 dc=600m type=dc freq=frf dbm=vrf pacmag=1
V1 (LO 0) vsource type=pulse val0=0 val1=1 period=tlo width=d*tlo
M0 (IF LO RF 0) N_12_RF wf=5u lf=120.0n nf=4 m=1
R0 (IF 0) capacitor c=c1
simulatorOptions options reltol=1e-3 vabstol=1e-6 iabstol=1e-12 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
pss  pss  fund=500M  harms=100  errpreset=moderate  annotate=status
pac  pac  start=1K  stop=500M  maxsideband=2  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

The conversion gain for h=-1 is shown below. I am getting a positive gain whcih doesn't make any sense to me .

Please advise what is wrong with this way of simulating mixer conversion gain.

The gain at 10MHz If calculated by using pss analysis followed by a dB20 peak measurement comes as  -4.7dB. Test bench looks like (c1=500f)

 // Library name: MIXER_CHARACTERIZATION
// Cell name: RX_MIXER_FUNDAMENTAL_RZ_MOS_SW
// View name: schematic
R0 (IF 0) capacitor c=c1
M0 (IF LO RF 0) N_12_RF wf=5u lf=120.0n nf=4 m=1
V1 (LO 0) vsource type=pulse val0=0 val1=1 period=tlo width=d*tlo
V0 (RF 0) vsource dc=600.0m type=sine ampl=vrf freq=frf
simulatorOptions options reltol=1e-3 vabstol=1e-6 iabstol=1e-12 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
dcOp dc write="spectre.dc" maxiters=150 maxsteps=10000 annotate=status
dcOpInfo info what=oppoint where=rawfile
pss  pss  fund=10M  harms=200  errpreset=conservative
+    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
                                     

Thanks

With Best Regards

Vishal

Hi Andrew,

Sorry for not specifying the problem correctly. I am not getting correct gain (loss) out of the passive mixer . My test bench looks like following:

c1=500fF

Conversion gain was calculated using pss+swept pac. For pss analysis , # of harmonics set to 0 . Port0 is dc type (based Spectre RF simulation manual)  . In Swept pac # of sidebands  was set to 2. The input.scs looks like following:

// Library name: MIXER_CHARACTERIZATION
// Cell name: RX_MIXER_FUNDAMENTAL_RZ_MOS_PSF_PXF
// View name: schematic
PORT0 (RF 0) port r=50 dc=600m type=dc freq=frf dbm=vrf pacmag=1
V1 (LO 0) vsource type=pulse val0=0 val1=1 period=tlo width=d*tlo
M0 (IF LO RF 0) N_12_RF wf=5u lf=120.0n nf=4 m=1
R0 (IF 0) capacitor c=c1
simulatorOptions options reltol=1e-3 vabstol=1e-6 iabstol=1e-12 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
pss  pss  fund=500M  harms=100  errpreset=moderate  annotate=status
pac  pac  start=1K  stop=500M  maxsideband=2  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

The conversion gain for h=-1 is shown below. I am getting a positive gain whcih doesn't make any sense to me .

Please advise what is wrong with this way of simulating mixer conversion gain.

The gain at 10MHz If calculated by using pss analysis followed by a dB20 peak measurement comes as  -4.7dB. Test bench looks like (c1=500f)

 // Library name: MIXER_CHARACTERIZATION
// Cell name: RX_MIXER_FUNDAMENTAL_RZ_MOS_SW
// View name: schematic
R0 (IF 0) capacitor c=c1
M0 (IF LO RF 0) N_12_RF wf=5u lf=120.0n nf=4 m=1
V1 (LO 0) vsource type=pulse val0=0 val1=1 period=tlo width=d*tlo
V0 (RF 0) vsource dc=600.0m type=sine ampl=vrf freq=frf
simulatorOptions options reltol=1e-3 vabstol=1e-6 iabstol=1e-12 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
dcOp dc write="spectre.dc" maxiters=150 maxsteps=10000 annotate=status
dcOpInfo info what=oppoint where=rawfile
pss  pss  fund=10M  harms=200  errpreset=conservative
+    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
                                     

Thanks

With Best Regards

Vishal