443 



Xe ~: 1 Xo 



— *• Go 1 * 



Let: Xe= Loop Error 



Xj- Loop Input Command 



Xo = Loop Output 

 In Search Loop, X, Contains Signals to Move Antenna and Stabilize it in Space. 

 It is Desired to keep the Loop Error Xe Less Than a Particular Magnitude |Xe| 



Since 



I X; I IX, I 



Go»l 



Xi X, I 

 IXJ= W — for 



iGol 



|X/| As a Function of Frequency is Known and |Go| 

 As a Function of Frequency is Found as Desired 



Fig. 8-30 Derivation ot Required Loop Transfer Function. 



calculations can be made for other frequencies, resulting in the circled 

 points shown in Fig.. 8-31. These points define the 7nini7nu?n open-loop 



Low-Frequency Asymptote 

 For Kv=400 



1000 



0.1 



01 1 I I 1 1 m il I I 1 1 m il I I I m ill i i i ii 



1.0 10 100 



wi FREQUENCY (rad/sec) 



Fig. 8-31 Search Loop: Open-Loop Transfer Function. 



