TRANSMISSION PROPERTIES OF CLOGSTON TYPE CONDUCTORS 705 



The dotted curve shown on Fig. 4 gives the skin depth in solid copper. 

 It will be noted that the copper layer thicknesses become smaller and 

 smaller fractions of the skin depth as the frequency increases. This is 

 also evident from (1) and (10) above, which show that the copper layer 

 thicknesses are inversely proportional to the frequency, while the skin 

 depth is inversely proportional to the square root of the frequency. 



The effect of fill is illustrated in Fig. 5 for a 375-mil Clogston I cable, 

 for fill factors of one-eighth, one-quarter, and one-half. It will be noted 

 that the attenuation increases rapidly with decrease in fill, accompanied 

 by an increase in the frequency band over which the attenuation is flat. 

 The attenuation of a completely filled Clogston II cable is also shown 

 for comparison. 



The above estimates are based on ideal conditions; that is, it is as- 

 sumed that the laminated structures are perfectly uniform. The effects 

 of departures from ideal are not shown by the approximate methods 

 used in this paper, but it has been shown by Morgan^ that even small 

 departures from ideal conditions will result in increases and irregularities 

 in attenuation, and a decrease in the band over which the attenuation is 

 approximately uniform. 



100 

 80 

 60 



J 40 — 



J 



;30 — 



uj20 

 Q. 



CD 10 

 8 

 6 



LU 8 



Q 



D 

 Z o 



I.O 

 0.8 



20 40 60 100 200 400 600 1000 2000 4000 



FREQUENCY IN KILOCYCLES PER SECOND 



Fig. 5 — ■ Attenuation of Clogston I. 



10,000 20,000 



^ Loc. cit. Part II, pages 1161-1201, 



