OTHER L-C FILTERS 

 or Z-C 2 = 2i?2Q(Ci + C2) 



(3) The coefficient of (J- must be zero. Therefore 



2LC2 = R\C^ + Ca)^ 

 Combining (2) and (3) it emerges that Cg = 3Ci (i) 



Putting this result back in (3), we find ^ ^ 3 ^1^^ ^"^ 



3 

 Using (i) and (ii) in (1) we get coc = ^RC ^ 



These are not quite in the form required for design. Re-arranging (iii) 



3 

 C2 = w^ — is one design equation (a) 



from (i) 



Ci = ^rz, — is another (b) 



IRoiQ 



Substituting (b) in (ii) gives 



L = -7. — as the third (c) 



3we 



Combining (a) and (c), it emerges that the section cuts off at 



\LC^ 



95 



