FILTER-TYPE CIRCUITS 



207 



between slots. They will be most accurate for structures with slots longitu- 

 dinally far apart compared with the transverse dimensions, and least ac- 

 curate for structures with slots close together. They do, however, form a 

 valuable guide in understanding the performance of such structures and in 

 evaluating the effect of the ratio of energies stored in the fields at the two cut- 

 off frequencies. 



Fig. 4.19 — Phase shift per section, Q, vs radian frequency, w, for the conditions of Fig 

 4.18. 



It is most likely that the voltages across the slots would be of most in- 

 terest in connection with the circuit shown in Fig. 4.10. We can rewrite 

 (4.41) in terms of Bt and Bi, 



r-/p = 



1 



2(1 - ^BJBt){-BtB,) 



1/2 



(4.49) 



We see that V'^/P goes to at 5^ = (w = wr) and to infinity at jB/, = 

 (w = coi,). In Fig. 4.20 assuming (4.46) and (4.47), (FVP)(coz,CLWrC7-) is 

 plotted vs CO for CJCt =1,3, 10. 



Let us consider another circuit, that shown in Fig. 4.11. We see that this 

 consists of a number of resonators coupled together inductively. We might 

 draw the equivalent circuits of these resonators as shown in Fig. 4.21. Here 

 L and C are the effective inductance and the effective capacitance of the 

 resonators without irises. They are chosen so that the resonant frequency 

 Wo is given by 



COo 



(4.50) 



