naalald
Full Member level 4
When I simulate the modulator in simulink the SNR is 62 dB but when I simulate it in hspice it is around 24 dB. The modulator seems to work well in hspice and the output waveforms are correct. I guess maybe there is some mistakes in calculating fft. Here is what I use:
.tran 1u 1.002 UIC
.fft v(no+,no-) np=63131 start=2m stop=1.002 window=hann freq=1 fmin=1 FMAX=540
The sampling frequency is around 63131. The output waveforms and FFT of both simulink and hspice are as below:
The input and output in simulink:
The input and output in hspice:
The FFT in simulink:
The FFT in hspice:
Any ideas?
Thanks.
.tran 1u 1.002 UIC
.fft v(no+,no-) np=63131 start=2m stop=1.002 window=hann freq=1 fmin=1 FMAX=540
The sampling frequency is around 63131. The output waveforms and FFT of both simulink and hspice are as below:
The input and output in simulink:
The input and output in hspice:
The FFT in simulink:
The FFT in hspice:
Any ideas?
Thanks.