Design and implement of a straight coupled transmission line cell for generating dominant E/H-field

The operating characteristics of the dominant E-mode and dominant H-mode were investigated using a newly developed straight coupled transmission line (SCTL) cell that made it possible to generate standardized TEM waves at up to 220 MHz. The SCTL cell, modeled via the Newton-Raphson method combined with the method of moments, exhibits high field uniformity within a space of 25×25×25 (cm³). Various operating characteristics were studied by measuring the electric and magnetic field characteristics of the SCTL cell with dominant E-mode and dominant H-mode relative to frequency, power, and position in a 3-dimensional coordinate system. Resonant frequencies were measured for different E/H-field distributions of the SCTL cell, and the results were consistent with the numerical analysis. This new SCTL cell could be used in electromagnetic susceptibility (EMS) assessments of near E/H-fields, as well as in interference measurements.