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BELL SYSTEM TECHNICAL JOURNAL 



wliicli follows immediately from equation 23 of Appendix A on the assump- 

 tion that gi — g2. Fig. 38 shows the results; g proves to be proportional 

 to the fifth power of the window width, over a very large range of values 

 of g. A knowledge of this relationship permits one, with the aid of equa- 

 tions 23, 24, 25, 26, and 27 of Appendix A to calculate the window size 



Fig. 38 — The relationship between window conductance (g) and window width for the 721A 



test cavity 



necessary to give any desired conditions of match, insertion loss, and leakage 

 power. 



APPENDIX C 



The ATR Box 



The value of the input impedance of the ATR is given b}^ equation 29 

 with h equal to zero so that 



Z = 



5i 



COo 



+ h 



which reduces to 



(31) 



(32) 



for the in tune case. This impedance is in series with the magnetron branch 

 and hence restricts the possible range in values for the impedance at plane 

 AB. Defining as F the fraction of the available power which is not ab- 

 sorbed by the ATR, then from Fig. 39 with the admittance of the receiver 

 branch assumed to be biB, 



F = 



(2 -f G)\-\- B'- 



(33) 



