Design and Validation of a Low-Cost Triaxial 5G RF-EMF Exposure Sensor

A low-cost monitoring network, to measure radio frequency (RF) electromagnetic field (EMF) exposure induced by 5G, is required for risk communication and to support research into long-term health and ecological effects related to 5G technologies. A low-cost triaxial fifth generation (5G) RF-EMF exposure sensor was designed, calibrated, and validated in the field, using a commercial network. The sensor uses a triaxial antenna-based measurement design and is able to measure the exposure induced by 5G communication in the n78 (3300–3800 MHz) and the n77 (3300–4200 MHz) frequency band up to 3900 MHz. The sensitivity of the simultaneous analog-to-digital converter (ADC)-based triaxial sensor is 0.06 V/m, while having a combined uncertainty <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${u}_{c}$ </tex-math></inline-formula> of 3.12 dB. The sensor was tested indoor and in two outdoor environments (private and commercial 5G networks). The maximum measured electric-field level induced by 5G (n77 band) was 0.89 V/m [500 m from a commercial base station (BS)] and 2.87 V/m (60 m from a private BS), which are 1.5% and 4.8% of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines, respectively. A second measurement campaign was used to compare the values of the electric field captured by the novel triaxial 5G sensor and commercial measurement equipment (SRM-3006). The average values of the electric field registered by the triaxial 5G sensor differ on average 2.8 dB from the values of the SRM-3006, which is within the measurement uncertainty of the SRM-3006.