AnsweredAssumed Answered

More info on Low Power threshold

Question asked by jinojs on Jun 21, 2015
Latest reply on Jul 28, 2015 by tlili

Hi,

 

When we tested RF path using KC705 and AD9364, we observed a power difference (additional gain of about 2dB).

To collect more data for analyzing, we ran more tests with different input power levels and observed the register 0x2B8. There we saw most of the time, the value was 0x20 (the average signal power has dropped below the low power threshold).

 

By seeing this, we ran more tests by changing the 'Low Power Threshold' value in the init param.

Do you have some more information about this threshold? Is there a max limit for this?

I see that the register 0x114 gets the value that is double of this threshold value in the main.c code. I believe it is because the resolution is 0.5dB/ LSB.

 

The test results with different power levels and Rx gain (MGC) are given below.

 

     

Input Power dBmLow Power Threshold (in Software)Rx GainReg 0x2B8 – Overload threshold
-19.42400x00
-19.52400x20
-40 to -1106000x00
-35.34000x00
-35.44000x20
-25.43000x00
-25.53000x20
-40 to -1105000x00
-40 to -1104800x00
-43.14400x20
-53.144100x20
All44600x00
-93.144500x20
-101.144550x20
All44580x00
All44570x00
TBD44560x20
-90.224710x00
-90.324710x20

 

 

The observation is that for values above 48, the threshold doesn't seem to have the effect. Is there a max limit?

Please share if you have more info on this.

 

Thank you,

~Jinoj

Outcomes