Senstar Corporation B76060 사용자 설명서

 

The driver amplifier was implemented using a NEC/CEL NE85639. The driver amp has 
approximately 9-11 dB of gain at its output.  

The driver amplifier uses a software settable bias circuit. During the factory test, the microcontroller 
will set the bias level of the driver amplifier by varying the quad DAC output voltage accordingly 
(MAX 533-pin 2) while measuring the bias current and/or output power. This bias set point effectively 
sets the current and gain of the driver amplifier stage.  

To minimize gain variation over temperature, the driver amplifier implements a thermistor (RT1) in 
its bias circuit. The negative temperature coefficient, thermistor’s resistance varies inversely with 
temperature to adjust the bias current in the device. This keeps gain constant over the environmental 
conditions defined for the PPD. 

 

The driver amplifier feeds the final power amplifier stage through a simple band pass filter consisting 
of a parallel inductor-capacitor in shunt with the driver amplifier’s output. This provides spurious and 
out-of-band rejection prior to final stage amplification.  

 

The final amplifier was implemented using a NEC/CEL NE85639 bipolar RF transistor. The final 
amp has approximately 9-11 dB of gain at its output.  

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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