Temperature-Dependent Over-the-Air Measurements of Total Isotropic Sensitivity for Minimum Uncertainty

Abstract

Characterizing the receiving performance of a radio system in current and future commercial communication devices is a significant concern for ensuring the reception of good quality signals and, more importantly, a reliable and stable connection to the base station antenna. The receiver performances are evaluated following the standardized method based on the total isotropic sensitivity (TIS) measurement. However, the current standard may not be accurate as it assumes that transmitters operate at their maximum power levels, which is not always true in real-world usage. Furthermore, different devices have varying maximum power levels, and the radio sensitivity measured depends on the device’s current temperature; therefore, it is affected by heat generation and dissipation. This can lead to ambiguity in TIS measurements. To address this, this paper suggests a new TIS method that measures TIS at the device’s thermally stable condition, thus redefining TIS not a single value but rather as a function of the transmitter’s power, reducing uncertainty and ambiguity in TIS measurements for wireless and 5G devices. Based on measurement results in this paper, the TIS measurement exhibits a variability of up to 1 dB due to the effects of temperature and transmitting power levels, distinct from the inherent measurement uncertainty of 0.28 dB specified by the standard. A more complex yet accurate measurement procedure is proposed while varying the power level. The proposed method is applied and experimentally verified, demonstrating its usefulness to extract the TIS profile instead of a single value, with a result of the TIS variation as a function of the transmitting power.