Need to measure the RF power( continuous unmodulated signal) of our custom board

[sunaina]

We need to measure the RF power(continuous unmodulated signal) of our custom board based on nrf5340 using spectrum analyzer. please suggest the steps and tools to perform the mentioned test.

[Priyanka]

Hi,

Please make sure that your custom board has an RF test point similar to the nRF5340 DK, which uses a small coaxial connector (SWF type, Murata MM8130-2600). This allows you to connect a test probe (Murata MXHS83QE3000) with an SMA connector to your spectrum analyzer. When the test probe is connected, the onboard antenna is disconnected, and the RF signal is routed to the probe.

https://docs.nordicsemi.com/bundle/ug_nrf5340_dk/page/UG/dk/hw_rf_measure.html 

Program your board with the Radio test sample . This allows you to configure the radio to output a continuous unmodulated carrier, which is suitable for RF power measurements and certification testing.

Attach the test probe to the RF test point on your board and connect the SMA end to your spectrum analyzer. Use a terminal emulator (e.g., PuTTY) to connect to your board’s UART interface. You can make use of the CLI commands provided by the radio test firmware. On the spectrum analyzer, observe and measure the output power at the set frequency.

-Priyanka

[sunaina]

Hlo,

Where should i have to configure the UART interface in the radio test sample that we are using in our custom board. we are using TX=P0.8 and Rx = P0.9 in our custom board. So please suggest regarding these requirements.

[Priyanka]

Hi,

You would need to modify the the device tree overlay for your board. You should update the uart0 node to assign the correct pins.

 nRF52840 DK set UART RX to P0.09 

-Priyanka 

[sunaina]

Thanks Priyanka,

The UART is working Properly and i see the logs but how should i send the CLI command in putty . Why  I am not able to type the command in  putty window. 

The logs are written below that came in putty but i am not able to type the command :

" *** Booting nRF Connect SDK v2.9.1-60d0d6c8d42d ***
*** Using Zephyr OS v3.7.99-ca954a6216c9 ***
Starting Radio Test sample
Clock has started
radio_test:~$ ** Using Zephyr OS v4.0.99-f791c49f492c ***
[00:00:00.517,547] <inf> sync_rtc: Updated timestamp to synchronized RTC by 8297 ticks (253204us)
radio_test:~$  "

so please suggest how i type the CLI command.