Design and Implementation of A Novel RF Rectangular Coaxial Coupling Structure for Pass-Through Voltage and Current Probes

This paper describes the design of a novel radio frequency (RF) rectangular coaxial coupling structure (RCCS) for a pass-through voltage and current (VI) probe, intended for use in high-power transmission line monitoring. The RCCS comprises a rectangular coaxial cavity, a capacitive voltage probe and an inductive current probe. Each of these components is designed to enable the simultaneous detection of the voltage and current of the inner conductor of the coaxial line. Simulation results indicate that the RCCS exhibits excellent matching performance with a reflection coefficient less than $\mathbf{-5 0} \mathrm{dB}$ and a transmission loss less than 0.005 dB over the frequency range of $\mathbf{1 0-1 0 0} \mathbf{~ M H z}$. The RCCS is demonstrated to be capable of maintaining stable outputs over the $10-100 \mathrm{MHz}$ frequency range, with an upper power limit of up to 18 kW, which is sufficient to meet the demands of high-power scenarios.