Above 5.35GHz the tinySA Ultra uses harmonic mixing. As the mixer in the tinySA is not designed for this, the conversion loss varies and you may have to calibrate out some variation.
To check if this is needed set the tinySA to a center frequency 5.35GHz, span 100kHz, RBW 300kHz and apply an input signal at 5.35GHz. When your device needs calibration you will see a step in the measured level at 5.35GHz
The compensation for this change in conversion loss is done by the CONFIG/LEVEL CAL/CALIBRATE above 5.34GHz command.
To eliminate this step, provide a 5.34GHz input signal between -50 dBm and -10 dBm and execute the CALIBRATE above 5.34GHz command.
When successful the step should be gone.
Alternative harmonic mode level calibration approach
It is not always possible have an 5.34GHz generator with sufficient accuracy. Although a bit more complex, it is still possible to calibrate the harmonic jump by following these steps.
- Perform a regular below 5.34GHz calibration.
- Tune a signal generator to the closests frequency below 5.34GHz.
- Set tinySA Ultra attenuation to automatic mode
- Start with an output level of the generator between -10dBm and 0dBm
- Reduce the output level of the generator such that internal attenuation becomes 0 dB
- Measure the output level of the generator with the tinySA.
- Tune the signal generator to the closests frequency above 5.34GHz while keeping the same output level
- Measure the output level of the generator with the tinySA
- Use the console command "leveloffset harmonic" to tune the measured level to be the same when measured below 5.34GHz.
- Use the console command "saveconfig" to permanently store the leveloffset harmonic setting.
