REFLEX OSCILLATORS 



If R varies as co', we see that we could then write 



G^ = GnW-K 

 Here Gli is the conductance at a frequency wi . 



S39 



(10.11) 



(10.12) 



1000 

 800 

 600 



100 

 80 

 60 





05 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 



TRANSIT ANGLE, Gg , IN RADIANS 



Fig. 52.- — The reciprocal of the square of the modulation coefficient is a function of the 

 gap transit angle in radians for the case of fine parallel grids. 



As an opposite extreme let us consider the behaviour of the input conduct- 

 ance of a coaxial line. It can be shown that, allowing the resistance of 

 such a line to vary as oj , the input conductance is 



Gt = ^C0*CSC2(C0//C). 



(10.13) 



Here t is the length of the line and C is the velocity of propagation. If 

 Gl given by (10.12) and Gi of 10.13 give the same value of conductance at 

 some angular frequency wi then it will be found that for values of t typical 

 of reflex oscillator resonators the variation of G( with w will be significantly 

 I less than that of Gl • Although typical cavities are not uniform lines 

 I (10.13) indicates that a slower variation than (10.12) can be expected. 

 It will be found moreover that the shape of the power output vs frequency 

 i curves are not very sensitive to the variation assumed. Hence as a rea- 

 sonable compromise it will be assumed that the resonator wall loss varies as 



