E
Erik Wanta
Guest
I have a current driven common emitter amplifier and I am trying to
measure distortion with the fourier analysis. My netlist is below:
//note term setting to perform fourier on collector current
FOUR0 fourier fund=1M active=yes harms=5 term=Q0:c
I1 (0 Vi) isource type=sine sinedc=0 ampl=1.5m freq=1M
V0 (vcc! 0) vsource dc=10 type=dc
Q0 (Vo Vi 0 0) npn
R0 (vcc! Vo) resistor r=15
I0 (vcc! Vi) isource dc=3m type=dc
I run a transient and get the following output. Note that it is
giving the results in volts, however I was expecting results in amps
as I am specifying that I want fourier run on the collector current.
I am getting about 76.5mA peak output current so I think it should
read mA. Any ideas why volts?
========================
Fourier Analysis `FOUR0'
========================
Fundamental frequency = 1 MHz.
Fundamental period = 1 us.
Fourier components of V(Q0:c) for the interval from 0 s to 1 us:
DC = 196.361 mV.
Harm: Absolute Absolute Relative Relative
Magnitude Phase Magnitude Phase
1: 76.0435 mV -90.0001 Deg 0.000 dB 0 Deg <-
normalizer
2: 3.6818 mV -812.977 uDeg -26.300 dB 89.9993 Deg
3: 357.375 uV 89.9967 Deg -46.559 dB 179.997 Deg
4: 43.3991 uV 179.994 Deg -64.872 dB 269.994 Deg
5: 5.90672 uV -89.9795 Deg -82.194 dB 20.5566 mDeg
Total harmonic distortion = 4.86481 % (-26.2587 dB).
RMS value of computed spectrum (excluding DC) = 76.1334 mV.
RMS value of computed spectrum (including DC) = 210.604 mV.
Nonperiodicity (first/last point mismatch) = -407.84 fV (-536.325 p%).
---
Erik
measure distortion with the fourier analysis. My netlist is below:
//note term setting to perform fourier on collector current
FOUR0 fourier fund=1M active=yes harms=5 term=Q0:c
I1 (0 Vi) isource type=sine sinedc=0 ampl=1.5m freq=1M
V0 (vcc! 0) vsource dc=10 type=dc
Q0 (Vo Vi 0 0) npn
R0 (vcc! Vo) resistor r=15
I0 (vcc! Vi) isource dc=3m type=dc
I run a transient and get the following output. Note that it is
giving the results in volts, however I was expecting results in amps
as I am specifying that I want fourier run on the collector current.
I am getting about 76.5mA peak output current so I think it should
read mA. Any ideas why volts?
========================
Fourier Analysis `FOUR0'
========================
Fundamental frequency = 1 MHz.
Fundamental period = 1 us.
Fourier components of V(Q0:c) for the interval from 0 s to 1 us:
DC = 196.361 mV.
Harm: Absolute Absolute Relative Relative
Magnitude Phase Magnitude Phase
1: 76.0435 mV -90.0001 Deg 0.000 dB 0 Deg <-
normalizer
2: 3.6818 mV -812.977 uDeg -26.300 dB 89.9993 Deg
3: 357.375 uV 89.9967 Deg -46.559 dB 179.997 Deg
4: 43.3991 uV 179.994 Deg -64.872 dB 269.994 Deg
5: 5.90672 uV -89.9795 Deg -82.194 dB 20.5566 mDeg
Total harmonic distortion = 4.86481 % (-26.2587 dB).
RMS value of computed spectrum (excluding DC) = 76.1334 mV.
RMS value of computed spectrum (including DC) = 210.604 mV.
Nonperiodicity (first/last point mismatch) = -407.84 fV (-536.325 p%).
---
Erik