Different TX max power levels in RF ports

IoT Modules 5G Module
1

I have EVB-M2 v1.3 board with RM520N-GL 5G module.
I am testing this against Base Station Emulator, so I have full control of network parameters. I noticed that maximum TX power varies on different RF ports. This depends on band and technology.
E.g. NR SA n77 band (100MHZ BW):
RF1 max tx power (uplink)= -13dBm, RF2 max = +20dBm, RF3 = -14dBm, RF4 = -42dBm. So only RF2 power is what I am expecting. I am using direct RF cables between board and tester. Also just SISO is used, so it is a bit surprise that all RF ports sends same transmission but in different max power level. Also quality of signal is good, except on RF4.

However, if setting power level to specific value, e.g. -25dBm then power level on RF1…3 are correct. So power levels are just capped on certain level, except RF2.
I tried to re-attach these tiny RF cables between module and board, but no change on max TX power level.

Is this expected behaviour?
And is there any AT command or such that I can change how RF ports are used or configure Max RF power on each RF port?

2

Dear @JanS
Actually, different combinations have different connection for antenna. PRX, DRX, MIMO1,MIMO2.

3

Thanks,
Is there any document that describes combinations and how RF ports are used on each combination?

4

Dear @JanS
We don’t have the document, but I share a combinations for reference via Message, please check.

5

Thanks, this document was what I was looking for!