AD9361 External LNA

Hi Yossi,

Since your bypass gain is negative you would need to even further increase your high gain.

From the manual: "If the low gain value is negative then the Ext LNA High Gain should be offset by this amount and the Ext LNA Low Gain should be set to 0 (for example, high gain value = 15 dB, low gain value = −5 dB, program Ext LNA High Gain = 20 dB and Ext LNA Low Gain = 0 dB). This will prevent a step in the RSSI value when the external LNA goes from an on to an off condition."

I think the experts on the AD9361 design forum can give you better insights on how to handle this case.

-Michael

Moved to AD9361 Design Support.

-Michael

Hi Yossi,

From my experience the RSSI is not reported correctly when the external LNA is bypassed. See here - AD9364 RSSI issue

The 12C and 12D registers are used only for RSSI report, they do not affect the AGC operation. Your gain table should contain correct gain settings for LNA on and LNA bypass scenarios, in order to maintain linear AGC response.

Best regards,

Oleg.