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BELL SYSTEM TECHNICAL JOURNAL 



for C is physically parallel to those for A and B and is connected to them 

 through a broad-band waveguide taper. Connection D is made through a 

 relatively narrow band coaxial and probe arrangement. Figure IV-6 il- 

 lustrates one of the waveguide band reflection filters. In this filter reflec- 

 tion occurs at three resonant rods, each tuned by an adjustable capacita- 



WAVEGUIDE-x 



^ WAVEGUIDE CHANNEL FILTERS 



INPUT 



TO I 



RECEIVER T 



4030 MC 



4190 MC W\ 



"--TERMINATIONS 



•24 -20 -16 -12 -8 -4 4 8 12 16 20 24 



FREQUENCY IN MEGACYCLES PER SECOND .(FROM MID-BANO) 



Fig. IV-9.— Transmission loss for the filter of Fig. IV-7. 



tive plug at one end. These rods are placed perpendicular to the electric 

 vector of the guide and are coupled to it by means of adjustable screws placed 

 over them in the wide wall of the guide. 



Channel dropping units for five channels in the 4,000 megacycle region 

 were made up of these components and suitable quarter wavelengths of 

 guide. These units were connected in sequence as shown in Fig. IV-7 and 

 adjusted systematically. The electrical performance of the resulting five- 



