684 THE BELL SYSTEM TECHNICAL JOURNAL, MAY 1954 



-40 



-2 



iH-0.8 

 o 



O -0.6 

 O 



O -0.4 



-0.2 



-0.1 

 -0.08 



-0.06 

 -0.04 



-0.02 



1.5 2.0 



CX IN RADIANS 



Fig. 20 — • Undriven line wave amplitude versus ex with unequal phase constants 

 and equal attenuation constants. The curves are periodic for larger values of ex. 



We consider first the case of {a\ — ao) negative, i.e., a lower attenua- 

 tion constant inthe driven line than in the undriven line. The effects of 

 unequal attenuation constants may be illustrated at the integrated 

 coupling strength ex = 7r/2 which, as Fig. 16 shows, results in complete 

 transfer of power to the undriven line when ai = ai and iSi = ^2 • Fig. 21 

 shows that the driven line wave amplitude £"1** is very small when 

 {ax — a-^lc is small, but is only Y^ db below unity when (ai — a2)/c is 

 about 55. Fig. 22 illustrates the way the undriven line wave amplitude 

 £"2** decreases as {ax — a^)lc increases. 



For integrated coupling strengths less than 7r/2, the effects of unequal 

 attenuation constants are not pronounced at small (ai — a-i)lc, but again 

 for large (ai — 0:2)/^, Ex'* approaches unity and 7?2** becomes small. 



