User's Manual

Appendix D: Sample Waveforms
AWG710&AWG710B Arbitrary Waveform Generator User Manual D-5
Table D-7: Nyquist pulse
File name NYQUIST.WFM Made with equation editor
Equation
clock = 1e9
size = 1024
k0 = 50e-9 ’data period
k1 = 512e-9 ’peak location
a = 0.5 ’excess bandwidth factor 0 to 0.5
“t” = (time - k1) / k0
“nyquist.wfm” = cos(a * pi * “t”) / (1 - (2 * a * “t”) ^ 2) * sinc(pi * “t”)
delete (“t”)
Descriptions
This is the impulse response of a wave shaping Nyquist filter. The
shoulder characteristics of this filter are referred to as “cosine
roll–off” characteristics, and the bandwidth used can be varied. This
waveform can be expressed by the following formula.
Here T is the data period and a is a value between 0 and 1. A wider
band is required for values closer to 1, where ripple is reduced and
implementation is easier.
Settings
Waveform points: 1024, Clock frequency: 1.0 GHz,
Output time: 1024 ns
Vt()
πat
T
--------


cos
1
2at
T
--------


2
–
----------------------------
πt
T
-----


sin
πt
T
-----
----------------------
⋅=