I attempted to utilize the BladeRF SDR for signal power measurement. My approach involved connecting the signal generator directly to BladeRF's RX 1, using a sinusoidal wave at 400 MHz with a power level of -35 dBm. MATLAB was employed to control the SDR, and the signal power was calculated using the formula: rms(x)^2. After 1 hour of measurement, a significant deviation was observed between the final and initial measurement results (refer to Figure 1, Iteration number: 1 iteration is equivalent to 2s ). Figure 2 illustrates the temperature readings from the internal temperature sensor of the SDR.
After approximately 1 hour of measurement, I incrementally increased the input power levels from the signal generator to -25 dBm and -20 dBm, respectively. The deviation exhibited a linear increase corresponding to the rise in input power.
My inquiry is as follows: Is this deviation normal, and what could be the reason for the substantial deviation attributed to heating effect
Please note: the AGC was set to manual mode and the gain was always 0 dB at Rx1.
Thank you.
Figure 1:
![Image](https://private-user-images.githubusercontent.com/87070539/286215703-c6ff9efc-9a43-4eab-bfe6-7f13ded8a8ce.jpg?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.qb7Xf3Gi3pXvSMRdo-GiG4m2JpEi-YYyl8bRoLr-Zfg)
Figure 2:
![Image](https://private-user-images.githubusercontent.com/87070539/286215854-52d9e2cc-da19-4026-aef9-734e1863b0a0.jpg?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.fxNXP3x0ts8EMF3sDsvsFUIP9ifEGNGHuVE_ITnJMMQ)