Справочник Пользователя для HIWAVE Inc HW-RFR900T

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2.8. RF Debug Tab 
The transmission wave propagates from power amplifier through directional device 
(circulator), and coax cable, and is transmitted by an antenna. Leakage or reflections on 
this path increase reflected (transmission) power level of the un-modulated carrier at the 
receiver input. (self jamming) High level of reflected power affects the receiver operation. 
To check the reflected power level we have integrated a diagnostic system in the AS3990 
which observes the amplitude and phase of the down converted received carrier. The 
result can be converted by DAC and read by the MCU (see device specification for 
details). 
In the RF debug tab the amplitude and phase of the received carrier (reflected power) is 
shown graphically. The acceptable levels are marked by green and yellow marks. On the 
left side you can also observe the two values coming directly from the ADC conversion, 
their absolute value, phase and approximate reflected power calculated to dBm. 
 
Update soft key is used update the readout on selected frequency. Scan soft key is used 
for continuously update. Sweep key is used to show results in a frequency domain using a 
wide frequency sweep. It is also possible to store the response shape by pressing calibrate 
key and in next sweep observe only the difference between actual reflectivity and the 
stored previous one.