how to adjust output power of the adf5901?
ADF5901 output power is set by using TX_REF_CAL_REF_CODE (Register 1).
This should be followed by the RECALIBRATION SEQUENCE page 23 of ADF5901 data sheet,
We have been trying to modify the Tx power and then going through the recalibration sequence. The problem is that we want to access the R9 register through the ADI - Radar-Eval-Software Platform 3.10, but this is not present in the GUI.
According to the sheet we need to input 0X2A20B929 into R9, but we have 0X2800B929.
The other problem is that we are using the SDP-H1, which works nicely with the ADI-Eval Software 3.10, but it does not work with all the other software packages such as the EV-Radar-MMIC and the proprietary software for ADF5901 and AD4159.
Please find a screenshot attached.
Is there any way to resolve this problem from software?
All the best,
Pascual and Cristian
Hi Pascual and Cristian,
To change the amplitude on the output power you need to do the following
You can find the VCO amp cal codes on the datasheet
The setup is also on supported with the SDP-S or SDP-B boards and might not work with the SDP-H.
I have some questions obout Tx output power.
1. Does the REFin in ADF5901 relate to Tx outout power? I use ADF4159 and ADF5901 to get 24GHz , in my PCB board, the REFin pin of ADF5901 is suspended and has no input signal, and the Tx1 output power is still only -16dBm. I wonder the Tx output power is decided by the power of REFin pin and my design is wrong? The register1 of ADF5901 is the amplitude calibration reference code, so the power of REFin pin is the reference value for TX output amplitude calibration code?
2. What is the registers writing order after initialization sequence to get max output power? Just need write R0 and R1? What is the function of recalibration sequence? Does it decide the Tx output power? I notice that R7 should be 2A20B929 in datasheet, but only set to 2800B929 can the board work, why?
Thank you very much.
REFin is needed for VCO calibration and initialization on the ADF5901 to ensure the VCO is centered in the band of operation. As per ADF5901 datasheet, REFin frequency range is 10MHz min. and 260MHz max. As said, REFin is for VCO_CAL which is to make sure the right frequency, namely the frequency reference, instead of the power reference. TX output power is controlled by using TX_AMP_CAL_REF_CODE. For the step, please refer to Ruairi's response on Jul 4, 2017. The differences between 2A20B929 and 2800B929 for R7 are the master reset and the clock divider. With 2A20B929, you have the master reset bit is 1, i.e. it will performs a reset of the device and all register maps, and you have the clock divider is set to 523, while with 2800B929, the master reset bit is 0, i.e. it returns the device to normal operation, and the clock divider is set to 11
May I ask some other questions related here? In my customer ADF4159+5901+5904 system, the two TX outputs of 5901 have different power, TX2 is about 5 dbm and TX1 is -15dbm. I am confused of it because the datasheet of 5901 said the two tx output can not be opend at same time,and the On/Off Isolation is 30dB , the tx to tx isolation is 25dB. I just referenced the initialization sequence of page 23 in the datasheet. So does it normal to test two output at the same time? If it does, should it be the same power? or did I misunderstand it?
Can you give me some debug suggestion to resolve the problem?
The ADF5901 should only have one Tx output enabled at a time. (Note: the registers setting allow both to be programmed ON but this should not be used)
If Tx2 is ON Tx1 should OFF and measure a signal >25dB down on Tx2 signal level.
thanks for reply. I got what you mean, the ADF5901 has two outputs, but only one enabled at a time. Now I wonder why we need two outputs here? what could we benifit from this than some other chips which only have one output? I mean in what situation we need this function? We designed our system of ADF4159+5901+5904, and just want to have two-transmitter channels and four-receiver channels. Can i understand it as we actually has only one transmitter channel?
In many cases only one Tx is used, but 2 Tx's are used for MIMO operation where the Tx's are alternatively switched ON/OFF to give virtual Rx channel and more system performance.
I got it ! It's really helpful, thank you, pwalsh!
I noticed that other developers using your ADI- Radar-Eval-Software Platform 3.10, but I can not find it in your official website, can I get it for free? Should I buy something to get it? I use the same chips, and it maybe useful for my design.
You need make request on Analog website.
Software Modules - How to Request Code | Analog Devices
I want to ask you, Is TX2 output 5dbm and Tx1 output-15dbm power after 5901 is initialized? Are you use the RECALIBRATION SEQUENCE or orther SEQUENCE, TX2 output power is only -9dbm After I initialize 5901, what is the reason? thans you.
I have tried the INITIALIZATION SEQUENCE and then the RECALIBRATION SEQUENCE ,but the output power is also very low.
First ,i don't why the datasheet have so many mistakes. The register explaination is different with the way that you use it.
Second ,why the output power can't be modified?
Finally,what's the way to make the chip work at 24.125G and output power at 8dBm?
In order to do the troubleshooting, could you please show the circuit block diagram of your test, and all those SPI commands you sent?
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