Analog Devices AD9361 User Manual

AD9361 Reference Manual UG-570
| Page 47 of 128
CUSTOM GAIN TABLES
OVERVIEW
Analog Devices supplies gain tables to use with the AD9361, but
some applications require modifying those tables to optimize the
RF performance (using an external LNA or creating 3 dB gain
steps for example). This section shows how to modify the gain
tables that the AD9361 uses for all gain control modes. Once
created the custom gain table can be loaded into the AD9361
using the ad9361_load_gt function.
The various gain block indices map to approximate gain per the
following tables (all values for 2300 MHz). Note that these are
nominal values and some variation with carrier frequency,
temperature, and process is expected for the LNA and mixer
tables. For accurate gain vs. gain index values RF characterization
needs to be done with the specific customer configuration.
Table 27. LNA Gain vs. Index
Internal LNA Index Internal LNA Gain (dB)
0 3
1 14
2 17
3 21
Tabl
e 28. Mixer Gm Gain vs. Index
Mixer Gm Index (d)
Mixer Gm Index Gain (dB)
0 0
1 3
2 9
3 − 15 = Index + 11
Table 29. TIA Gain vs. Index
TIA Index Internal LNA Gain (dB)
0 −6
1 0
Table 30. LPF Index vs. Gain
LPF Index (d) LPF Gain (dB)
0 − 24 = Index
Table 31. Digital Index vs. Digital Gain
Digital Index (d) Digital Gain (dB)
0 − 31 = Index
Rev. A

Analog Devices AD9361 Specifications

General

Brand	Analog Devices
Model	AD9361
Category	Motherboard
Language	English