HAM) Winril IA/> /7\.I.V.S1//.S-.SY(J.V I'KR/ORMA.VCK 



50.S 



selectivity foUowiiif:; conversion lo iiUer-nu-diiite fa'(|uen(y. Microwave 

 receiving fillers afford enough selectivity to divert alternate hands into their 

 correct frequency-converting units without disturbing the other bands; and 

 microwave combijiing filters serve in the transmitting side of the repeater to 



BACK TO BACK(OVER_tOODB) 



FRONT TO BACK 

 (75 DB) 



^2 



4040 

 I 1 



3960 

 I 1 



H h 

 1 1 



3880 



! 1 



BAND- 

 COMBINING 

 FILTERS 



4000 



3920 



I I ! 



3840 



I 1 



1 H 



I I 



BAND- 

 RECEIVING 

 FILTERS 



y 



FRONT TO BACK 

 (75DB) 



p;g_ 4 — Arrangement of Iwo-way Iwo-freciuency repeater of television type showing 

 spacing of bands and antenna discrimination. 



bring the bands into the common antenna with small loss and small mutual 

 disturbance.^^ The combining and separating processes are made easier by 

 the interleaving of transmitting with receiving frequencies. Interleaving 



19 W D Lewis and L. C. Tillotson, ".V Non-rellecting Branching Filter for Micro- 

 waves," Bell Sys. Tech. J I., Vol. 27, pp. 83-95, January, 1948. 



