First thanks for the answer
pancho_hideboo wrote on Jul 21st, 2008, 5:12pm:Why do you set local frequency(FUND2) as 1.1GHz while you state "Direct Conversion Mixer" ?
Sorry I wrote wrong in the last post. FUND2=1GHz.
pancho_hideboo wrote on Jul 21st, 2008, 5:12pm:What do you refer as disagreement ?
You seem to apply 16QAM signal with carrier frequency of 1.0GHz and Rsymb=20MHz as RF input signal.
Show me your constellation results.
If I use FUND1=FUND2=1GHz I obtain this constellation(Plot source with v(11).h(1,0)):
The plot off in and out has attach
IT's OK
But IF I will change the verilog source, add a second order intermodulation. I don't see the modification of constellation.
I'm thinking that the results of mixer h(1,-1) is different of the dc output h(0,0) but I would like to see in same time. What I think is correct?
pancho_hideboo wrote on Jul 21st, 2008, 5:12pm:To plot constellation you have to tune sampling timing of symbol.
I can't find even symbol_rate setting in your plot setup.
Do you understand difference of constellation and trajectory ?
Ok, I have used a EZWAVE for plotting the constellation, I have used a TCL archive for tune the sampling:
Quote: evalExpression { setAngleUnits("degrees") }
evalExpression { setTemperatureUnits("celsius") }
evalExpression { wf0=mag(wf("<teste/FMODSST>V(11).H(1,0)"))}
evalExpression { wf1=mag(wf("<teste/FMODSST>V(22).H(1,0)"))}
evalExpression { saida=complex(wf("<teste/FMODSST>VR(22).H(1,-1)"),wf("<teste/FMODSST>VR(31).H(1,
-1)"))}
evalExpression { saida1=complex(wf("<teste/FMODSST>VI(22).H(1,-1)"),wf("<teste/FMODSST>VI(31).H(1
,-1)"))}
evalExpression { C2211=constellationdiagram(wf("<teste/FMODSST>V(22).H(1,-1)"),5E-8,35E-9) }
evalExpression { C1110=constellationdiagram(wf("<teste/FMODSST>V(11).H(1,0)"),5E-8,35E-9) }
evalExpression { C3111=constellationdiagram(wf("<teste/FMODSST>V(31).H(1,-1)"),5E-8,35E-9) }
evalExpression { C2210=constellationdiagram(wf("<teste/FMODSST>V(22).H(1,0)"),5E-8,35E-9) }
evalExpression { C2200=constellationdiagram(wf("<teste/FMODSST>V(22).H(0,0)"),5E-8,35E-9) }
evalExpression { C2220=constellationdiagram(wf("<teste/FMODSST>V(22).H(2,0)"),5E-8,35E-9) }
evalExpression { C2230=constellationdiagram(wf("<teste/FMODSST>V(22).H(3,0)"),5E-8,35E-9) }
evalExpression { saidadc1=wf("<teste/FMODSST>VR(22).H(0,0)")+wf("<teste/FMODSST>VR(22).H(1,-1)") }
evalExpression { saidadc2=wf("<teste/FMODSST>VR(31).H(0,0)")+wf("<teste/FMODSST>VR(31).H(1,-1)") }
evalExpression { saidadcc=complex(wf("<calc>saidadc1"),wf("<calc>saidadc2")) }
evalExpression { Csaidadc=Constellation_wf4=constellationdiagram(wf("<calc>saidadcc"),5E-8,3.5E-8
) }
evalExpression { Csaida=constellationdiagram(wf("<calc>saida"),5E-8,3.5E-8) }
evalExpression { Csaida1=constellationdiagram(wf("<calc>saida1"),5E-8,3.5E-8) }
pancho_hideboo wrote on Jul 21st, 2008, 5:12pm:For example, constellation function of Agilent ADS is like following.
constellation(i_data, q_data, symbol_rate, delay)
Here symbol_rate and delay are required.
Even if there is no filter in your setup, you have to delay at least Tsymb/2-Tstep to plot constellation.
it's same of ADS
constellationdiagram(complex(i_data,q_data, T_symbol,delay)
pancho_hideboo wrote on Jul 21st, 2008, 5:12pm:Although I don't know eldoRF, I guess the above two statement combination is for envelope analysis.
Yes, It's same to ADS envelope analysis
trumpeu wrote on Jul 21st, 2008, 11:11am:.PLOT TMODSST V(11) V(22) V(31) V(12) V(13)
.PLOT FMODSST v(11) v(12) v(13) vr(22) vr(31) vi(22) vi(31)
In the above, there is no specification of harmonic to observe.
And my problem is that I don't see the dc off-set of second order intermodulation
thank you for attention