244 



BELL SYSTEM TECHNICAL JOURNAL 



is necessary. This means relatively long transmission lines between the 

 antenna and the rest of the repeater. If exact termination of the line by 

 the antenna impedance or by the filter input impedance were possible no 

 distortion would be produced, but in general there will be a slight mismatch 

 and a corresponding reflection of energy at each of these junctions which 



LINE ATTENUATION CONSTANT 

 LINE VELOCITY = V 



REFLECTION COEFFICIENTS ". V. 



=^ 



_ Zo-Zi . 



Zn+Z, ' 



I = E 



'^^2 .-oci e-J» 



Zo+Z, " 



TAN^ = iifTAN^ 



'l+p2-2/5C0S^^ 



r3 = 



Z0-Z2 

 Z0+Z2 



-*\ some }^FOR I = 0.94m 



■*\ 20 mc K- FOR I = 3.75 m 



-*►! smc [♦ FOR 1= 15m 



->t l.25mc (♦ FOR I = 6om 



\-p 



>v=3xio'°cm/sec 



\-p' 



I+/32_2pCOS-^^ 



Dmax-Dmin=4p-|^sec 



(/3«1) 



2T\ir (2n+i)7r (2n+2)7r (2n+3)7r (2rn-4)7r 

 4 7rl ^ 



Fig. VI- 1. — Effect of long lines on the amplitude and delay distortion of a repeater. 



will produce variations in the amphtude and delay of the signal throughout 

 the desired band. These variations may be greater than those produced 

 anywhere else in the repeater. 



The type of distortion originating in this way is illustrated by Fig. VI- 1. 

 In this figure there is represented an antenna of impedance Zi connected 

 by a line of length I and characteristic impedance Zo, to a load, Z2. In actual 

 practice this load is the impedance presented by the filter to the line from 



