This review offers a detailed examination of the current landscape of radio frequency (RF) electromagnetic field (EMF) assessment tools, ranging from spectrum analyzers and broadband field meters to area monitors and custom-built devices. The discussion encompasses both standardized and non-standardized measurement protocols, shedding light on the various methods employed in this domain. Furthermore, the review highlights the prevalent use of mobile apps for characterizing 5G NR radio network data. A growing need for low-cost measurement devices is observed, commonly referred to as “sensors” or “sensor nodes”, that are capable of enduring diverse environmental conditions. These sensors play a crucial role in both microenvironmental surveys and individual exposures, enabling stationary, mobile, and personal exposure assessments based on body-worn sensors, across wider geographical areas. This review revealed a notable need for cost-effective and long-lasting sensors, whether for individual exposure assessments, mobile (vehicle-integrated) measurements, or incorporation into distributed sensor networks. However, there is a lack of comprehensive information on existing custom-developed RF-EMF measurement tools, especially in terms of measuring uncertainty. Additionally, there is a need for real-time, fast-sampling solutions to understand the highly irregular temporal variations EMF distribution in next-generation networks. Given the diversity of tools and methods, a comprehensive comparison is crucial to determine the necessary statistical tools for aggregating the available measurement data. ... Read more

In this work we present calibration approaches aimed at mitigating the measurement error in testbenches featuring multiple sensor-nodes and operating over-the-air. Such errors can arise from fluctuations in component responses and mechanical tolerances of the setup. The calibration approaches are detailed for the case of the Antenna Dome measurement setup previously presented by the authors.In the current implementation, the Antenna Dome employs multiple dual linearly-polarized scalar sensing nodes, to enable real-time 2D (theta and phi) radiation pattern acquisition. The variation of the electrical response among the different sensing elements as well as their position, with respect to the nominal one, due to the mechanical tolerances, introduce systematic error in the generated radiation patterns.Over-the-air procedures to linearize the power conversion asymmetry within the dually polarized nodes as well as the linearity response across them are described. Proposed approach provides a reduction of the angular dependent error within ±0.5 dB across the various nodes. Moreover, to minimize the impact of mechanical deviations an over-the-air method is described to transfer the sensor coordinates from the mechanical reference system to the antenna under test one. ... Read more

In this contribution we present the hardware components, system architecture and software modules constituting the base of the TU Delft high speed Antenna Dome. The modular architecture together with the custom designed detecting unit cell allows for real-time 2D antenna characterization, providing user defined performance, optimized for the 5G FR2 mm-wave band. The various high frequency components (i.e., antenna, square-law detector) and logical subsystem composing the dual-polarization signal acquisition unit are described and evaluated for their performance. The routines and algorithm allowing for accurate 2D spatial interpolation and the system calibration/normalization are reviewed. Finally, preliminary measurement data of antennas operating in the FR2 band are presented. ... Read more