Appendix D: Sample Waveform Library

Nyquist Pulse Made with the equation editor. (NYQUIST.WFM)

Figure D(6: Nyquist Pulse Formula and Waveform

Constants

k0 is the period of the digital data used in communication or recording.

 

k1 is the pulse peak location. k2 is the excess bandwidth factor, and is a

 

value between 0 to 1.

 

 

 

 

 

 

 

Description

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.

 

cos￿paT t￿

sin￿pTt￿

 

V(t), +,

 

 

@

 

 

 

 

2

pt

 

 

1￿

￿

2at

￿

T

 

 

 

 

 

 

T

 

 

 

 

 

 

 

 

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: 1000

 

Clock frequency: 100 MHz

 

Output time: 10 ms

 

 

 

 

 

 

 

 

 

 

 

AWG2021 User Manual

D(9