Testing 5G PAs: from the Cable to OTA

From the concept phase to the production, the test of the RF Power Amplifier is very similar in all the stages. Traditional measurements like output power, VSWR, Efficiency, Linearity, etc, using well known methodologies, are collected to characterize the performance of the circuit. Even in the final BTS, the transmitter tests are compatible with the final evaluation of the PA. This is true in the current wireless cellular technologies, but that is changing in the upcoming use of 5G active antenna arrays. It is expected that due to different working conditions of the PA (due to for instance the coupling between antenna paths), additional measurement parameters will be needed. In addition, the integration level imposed by the frequency increase force to have mixed blocks (LNA, vector modulator, etc) in the same MMIC or package, which requires a more complex digital interface or even BIST structures. In this presentation, these topics will be addressed to highlight the importance of having different and additional testing methodologies like the OTA.