TRANSMISSION LOSS DUE TO RESONANCE OF CONVERTED MODES 905 



•lOr 



U° 



-12 

 -14 

 -16 

 -16 

 -20 

 -22 

 -24 

 -26 

 -28 



O -30 

 O 



^ -32 



-34 

 -36 

 -38 

 -40 

 -42 



-44 



■46 



-48 



-50 



0.1 



0.2 0.3 0.4 0.6 0.8 1.0 2 3 



TAPER LENGTH, L, IN METERS 



5 6 8 10 



Fig. 5 — Mode conversion of TE02 and TE03 relative to TEoi generated by a 

 conical taper. 



The relative levels of TE02 and TE03 conversions, which have been 

 calculated from unpublished work of S. P. Morgan are shown plotted in 

 Fig. 5 for the waveguide sizes employed in the millimeter wavelength 

 band. The conversions, 20 logio ro2 , are plotted in terms of the TE02 

 and TE03 powers relative to the TEoi mode power and are expressed in 

 db as a function of the taper length L, in meters. 



Fig. 6 shows the theoretical and experimental values obtained for 

 TEoi relative insertion loss. Since the minimum length of pipe tested is 



