I am working on Frequency Hopping Mux Mode. I prepared a setup for External Loopback for several Navassa RFICs. One Navassa is used for Tx and other 2 is operating on Rx. They are all loaded with exactly same FH Table. I connect Tx Port to a Rx Port externally. Then I analyze the Received Signal in FGPA.
Tx Signal level seems stable for each Frequency (Controlled via Spectrum Analyzer). But received signal strength varies depending on the frequency. There is approximately 6-8 dB difference between minimum and maximum level. The level pattern is same for both Rx devices(The frequency with highest and lowest level is same).
For example Rx input is at -20dB, the signal level after analyzing Rx data in FPGA is -18dB at 800Mhz, -22dB at 805MHz. The signal levels are consistent from run to run, e.g. 805MHz is always the lowest one.
The settings for Rx Gain is as follows: (SDK v24.1 is used)
- Rx Gain Control Mode : SPI
- Default Rx Gain Table is used. (The one mentioned in User Guide)
- Rx Gain Table index is set as 255 for all frequencies (Which means 0dB Gain/Attenuation)
- Rx Interface Gain is set as 0dB
- Gain Table Index is not controlled/changed by user via SPI or PIN in runtime.
- Rx_GainControl_Configure() function is used, but the mode is not AGC, so the parameters given in that function does not apply right? I can provide that configurations if needed.
When I changed the initial Rx Gain Table Index in FH Table, I confirm that the calculated signal level has changed accordingly. So I assume I am able to set Rx Gain Table Index correctly.
Best Regards
