Network Vector Analyzer Measurements and MATLAB Validation of Twin-Coil and Small-Coil Self-Resonant Frequencies

This dataset provides raw network-vector-analyzer measurements, original instrument records, MATLAB analysis code, and derived figures for experimental validation of the self-resonant frequency (SRF) of radio-frequency solenoids treated as distributed helical transmission-line structures. The primary twin-coil dataset contains complex Touchstone S-parameter measurements over 12–16 MHz with 501 frequency points and a 50-ohm reference impedance. The analytical model predicts a free-coil SRF of 13.481 MHz, while the NanoVNA Saver measurement record reports a minimum VSWR of 2.380 at 13.488 MHz, corresponding to a model-to-measurement residual of 7 kHz (approximately 0.052%). The record also reports a maximum S21 of -12.171 dB at 13.432 MHz. A second JNCRadio VNA 3G measurement record is included for a smaller coil with a theoretical SRF of 12.6865 MHz over an 11–13 MHz measurement span. The accompanying MATLAB script reconstructs input impedance from S11, plots S11 and S21, compares the theoretical and measured twin-coil SRF, and evaluates the frequency-grid contribution to the SRF extraction uncertainty. The dataset is intended as supporting material for reproducible validation of integer-ratio RF-solenoid and Knight/Ollendorff-type transmission-line modelling. The release does not include repeated independent sweeps, the separate 171 kHz Q-factor raw dataset, or lower-frequency tuned load-network data.