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BELL SYSTEM TECHNICAL JOURNAL 



type. In Fig. 25 are shown the distributions of mode frequency for a typical 

 resonator system unstrapped, and strapped with three of the types of 

 strapping shown in Fig. 24. 



It is possible to account, in quite simple terms, for the shift which takes 

 place in the mode frequency distribution when the anode is strapped. For 

 this purpose consider a double ring strapped system like that of Fig. 24 (d). 

 The role of the straps in determining mode frequency depends upon the 

 relative magnitudes of their shunt inductive and capacitive efifects. The 



12 3 4 



MODE NUMBER, n 



Fig. 25. — Plots of the variation of mode wavelength with mode number for a resonator 

 system, unstrapped, or strapped in different ways. Curve (a) is for the unstrapped anode 

 structure. Curve {b) is for the same structure strapped as shown in Fig. 24 {a), curve (c) 

 for the same structure strapped as shown in Fig. 24 {b), and curve {d) for the same structure 

 strapped as shown in Fig. 24 {d). It is to be noted how the wavelength increases for large 

 n and decreases for small ti as the "strength" of strapping is increased. 



capacitive effect of the straps for any mode depends upon the amount of 

 shunt capacitance added relative to that already present in the resonators 

 and upon the positions in the system to which they are connected. This 

 latter determines the average phase difference between the rings and thus 

 their potential difference per unit RF voltage excitation. Similarly, the 

 inductive effect of the straps depends upon the magnitude of their shunting 

 inductance relative to that in the resonators. However, the important 

 consideration concerning the points to which the straps are connected is the 

 phase differences between points along the resonator system to which a 



