Tektronix AWG2021 User Manual page 568

AWG2021 User Manual
Hamming Window. The hamming window is similar to a hanning window, but it
suppresses more the transmissivity for the side lobes next to the transmitting
bandwidth. Compared to FFT processing using a hanning window, the degree of
separation between two frequencies is greater, as can be seen in Figure F-10.
This window is particularly effective for separating close frequencies.
Window Function
Figure F 10: Hamming Window and Frequency Characteristic
Blackman Harris Window. Of the six window functions in this instrument, the
Blackman-Harris window has the broadest transmission bandwidth (and
therefore, lowest frequency resolution) and the lowest side lobe transmission
(and therefore, lowest leakage). This window is particularly suited for observing
wide range frequency spectra.
Window Function
Figure F 11: Blackman Harris Window and Frequency Characteristic
0 dB
-20
-40
-60
Freq. Magnitude
0 dB
-20
-40
-60
-80
-100
-110
Freq. Magnitude
Appendix F: Miscellaneous
3 dB Bandwidth
1.30
Highest
Side Lobe
-43 dB
3 dB Bandwidth
1.66
Highest
Side Lobe
-92 dB
F 21