THE FIELD DISPLACEMENT ISOLATOR 



889 



30 



25 



20 



15 



10 



0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 



LENGTH OF LOSS FILM IN INCHES 



4.5 



5.0 



5.5 



Fig. 12 — Attenuation versus length of resistance strip. 



'ohms/square. Variations of about d=30 ohms/square about this value 

 result in little deterioration in performance. 



Some further discussion of the perturbed dominant mode is of interest. 



jWe may think of the height reduction as primarily a dielectric discon- 



itinuity where we have effectively added a negative electric dipole den- 



Isity to a full height slab. Since this addition is smaller for the forward 



case (where there was initially a small electric field) than for the reverse 



case, we may expect the longitudinal components to be smaller for the 



forward propagating mode. The other type of longitudinal electric field, 



50 



-I 40 



O 

 UJ 

 O 



, 30 



If) 

 if) 

 O 



-■ 20 



LU 

 If) 



a. 



LU 



I '0 



a.^__ 



REVERSE LOSS 



FORWARD LOSS 



.J^ 



0.5 



0.4 



0.3 



If) 

 If) 

 o 



0.2 



0.1 



Q 



a: 

 < 



cc 

 o 



5900 6000 6100 6200 6300 6400 

 FREQUENCY IN MEGACYCLES PER SECOND 



Fig. 13 — Loss versus frequency. 



6500 



