v^'n^^Vz 



^envelope 



-0.2 -0.1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 I.I 1.2 1.3 



X /J-2J-1 \ t /Jj_~Xl \ 

 ~2 \~r r )~ ~2 \'~j — J — J ( offer Kinsman, 1965) 



Figure 2-5. Formation of Wave Groups by the Addition of Two Sinusoids 

 Having Different Periods 



2-26 



