COPPER OXIDE MODULATORS IN CARRIER SYSTEMS 333 



The input signal generator Fo is applied out of an input circuit 

 impedance Za, and the output signal is delivered to the output circuit 

 impedance Zh. Both Za and Zb in general will be functions of fre- 

 quency. 



\i Za = Zb = R at all frequencies it can easily be shown that the 

 circuit will operate most efficiently for 



R = <RrRf. (27) 



The signal input current will then be the only frequency in ia'. 



From the properties of lattice networks it follows that 



1 

 + 1 



''^^'^^ -^^^^' ^^^^ 



\Rr 



\Rs 



where 



Letting 



and 



m = 



+ 1 for positive half-cycle of carrier 

 — 1 " negative ' 



(I K 



4 / 1 1 



/(/) = — I cos ct — - cos 2>ct + 7 cos Set- 



TV \ 6 J 



k = ^ , (30) 



S+1 



V,k 4 



cos ct — - COS 3/ + Y cos 5c/- 



The magnitude of the single-sideband output current is 



and the efficiency 



(31) 



H^ = ^.-=-'J^ (32) 



V=-,k\ {^i) 



In addition currents flow in the output circuit at both sidebands 

 of all odd harmonics of the carrier frequency. These can be repre- 



