COAXIAL AND BALANCED TRANSMISSION LINES 

 and output voltages and currents we have 



2co/i 



279 



eo = ei 



r, J 7 Sin 

 Zcoli Zoi V 

 COS h ^r^ r- 



tan 



V 



la 



ti 



COS 



2co/i 



^ sin 



Zoi z^ 



2Z02 , w/2 



''tan 



z; 



— jiiZo^ 

 2co/i 



, sin^ — 



. ZCO/i , Z01 Z^ 



sin + -— j- 



V Z02 ^_^ '«J^2 



tan 



z; 



(11) 



. ei 



sin 



Icxili 



cos^ 





Zn 



C0/2 

 tan — 



The properties of symmetrical filters such as considered here are 

 usually specified in terms of the propagation constant F and the itera- 

 tive impedance K. These are similar to the line parameters used in 

 equation (1) and it can be shown that the same relations exist between 

 the input and output voltages and currents that exist in equation (1). 

 Hence comparing equation (1) with equation (11) we find 



cosh r = cos 



2coli 



. Iccli 



ry Sin • 



Zqi V 



2Zq^ C0I2 

 ''tan 



V 



K = Zo 



1 + 



call 



„ tan — 



Zqi v__ 



2Zoo ^ C0I2 

 " tan — 



V 



1 - 



'Ol 



cot — 



V 



(12) 



/Zqo . C0/2 

 tan — 



V 



The propagation constant F has the same significance as for a uni- 

 form line, namely that 



en 



en-\ 



-T-^ = ratio of currents or voltages between any two 

 ^"~^ sections in an infinite sequence of sections, 



