Metrological Verification of RF Measurement Chains for Real-Time In Vitro Bioelectromagnetic Experiments

Real-time in vitro bioelectromagnetic experimentation under radiofrequency (RF) exposure requires strict control of the conditions delivered to the sample, especially when coupled with sensitive electrophysiological recordings. Although dosimetric characterization of exposure systems is increasingly reported, the measurement chain and protocol used to set, monitor, and verify the delivered RF power are rarely described in sufficient detail, leaving a gap between system dosimetry and daily practice. This work presents a methodology for characterizing and verifying the RF measurement chain upstream of a real-time in vitro exposure system at 5G Frequency Range 1 (FR1) frequencies, from signal generation to the exposure device. Scattering-parameter characterization of the chain components is combined with continuous power monitoring to translate a target Specific Absorption Rate (SAR) into the corresponding generator setting. A bottom-up uncertainty budget is reported, and the measurement model is verified experimentally at 3.5 GHz on a representative chain configuration, with the deviation between predicted and measured reflected power remaining within the estimated expanded uncertainty. As a complementary check, real-time temperature monitoring confirms the absence of detectable thermal drift under a representative low-power exposure condition. Rather than system-specific dosimetric results, this work provides a reusable procedure for controlled and traceable RF exposure conditions.