Performing RF Calibration#

The crystal calibration for SiWx917 NCP IC can either be done in Burst Mode or Continuous Wave (CW) mode. For more details, refer to SiWx917 QMS Crystal Calibration App Note.

Setup#

Ensure the SiWx917’s RF port is connected to Spectrum Analyzer as shown below:

RF Calibration SetupRF Calibration Setup

Transmission in Burst Mode#

This mode requires a test instrument that supports modulation analysis where frequency error can be reported by the instrument directly.

Steps for Frequency Offset Correction#

  1. Set up the radio and start transmission.

    commander manufacturing radio --power 16 --phy 6MBPS --channel 1 --start -d <full opn> --serialinterface

  2. Check the frequency error on the instrument. Adjust the XO CTUNE values by providing the frequency error as input. Provide this frequency error as frequency offset. This value can be ranging from –255 to 255.

    commander manufacturing xocal --offset <Offset> -d <full opn> --serialinterface --skipinit --skipload

  3. Observe the updated frequency error on the instrument. If the frequency error is not within +/-2 KHz, a new round of frequency error can be processed via step 2. This process may be repeated until the frequency error is brought within the tolerance limit (+/-2 KHz).

  4. Store the XO CTUNE value in eFuse (OTP) or Flash. The radio transmission will stop.

    eFuse:

    commander manufacturing xocal --storeinefuse -d <full opn> --serialinterface --skipinit -skipload

    Flash:

    commander manufacturing xocal --store -d <full opn> --serialinterface --skipinit --skipload

Steps for Gain Offset Calibration#

  1. Set up the radio and start RF transmission in Burst mode.

    commander manufacturing radio --power 16 --phy 6MBPS --channel 1 --start -d <full opn> --serialinterface

  2. Measure the output power with the instrument that has the capability of measuring burst power. For example, Keysight instrument with modulation analysis measurement setting capability shows the burst packet power.

  3. Calculate the offset to meet the expected output power (16 dBm).

    Offset = ceil ((output power measure (dBm) + cable loss -- 16) * 2)

  4. Store the gain values for channel 1.

    commander manufacturing gain --ch1 <Offset> --skipload -d SiWG917M111MGTBA --serialinterface --skipinit

  5. Repeat from step 1 for channel 6 and 11. In step 4, replace --ch1 with --ch6 and --ch11 when measuring for channel 6 and 11 respectively.

  6. Stop the radio.

    commander manufacturing radio --stop --skipload -d SiWG917M111MGTBA --serialinterface --skipinit

Transmission in Continuous Mode#

Steps for Frequency Offset Correction#

  1. Set up the radio and start transmission.

    commander manufacturing radio --power 16 --phy CW --channel 1 --start --noburst -d <full opn> --serialinterface

  2. Measure the frequency on the instrument using peak search (use the instrument which supports spectrum mode/modulation).

  3. Adjust the CTUNE values by providing the frequency error as input. This is a frequency offset correction, with the value ranging from –255 to 255.

    Offset = measured frequency (in kHz) -- 2412000

    commander manufacturing xocal --offset <Offset> --skipload -d SiWG917M111MGTBA --serialinterface --skipinit

  4. Check the instrument and verify that the channel frequency is within expectations. If not, repeat from step.

  5. Store the CTUNE values. The radio transmission will stop.

    commander manufacturing xocal --store --skipload -d SiWG917M111MGTBA --serialinterface --skipinit

Steps for Gain Offset Calibration#

  1. Setup the radio and start transmission on channel 1.

    commander manufacturing radio --power 16 --phy 6MBPS --channel 1 --noburst --start -d SiWG917M111MGTBA --serialinterface

  2. Measure the output power (use the instrument which supports spectrum mode/modulation). Measure the integrated power in 20 MHz bandwidth.

  3. Calculate the offset to meet the expected output power (16 dBm).

    Offset = ceil ((output power measure (dBm) + cable loss -- 16) * 2)

  4. Store the gain values for channel 1.

     commander manufacturing gain --ch1 <Offset> --skipload -d SiWG917M111MGTBA --serialinterface --skipinit

  5. Repeat from step 1 for channel 6 and 11. In step 4 the replace –ch1 with --ch6 and --ch11 when measuring for channel 6 and 11 respectively.

  6. Stop the radio.

     commander manufacturing radio --stop --skipload -d SiWG917M111MGTBA --serialinterface --skipinit