Study on the Disc Sensor Based on the Cavity Mold Theory

Ultra-high-frequency (UHF) sensor is the vital component of a partial discharge detection system and its coupling performance is affected by structural parameters. On the basis of the cavity model theory, this paper studied the influence of the disc electrode diameter, the thickness, the dielectric constant of the dielectric substrate, and the position of the coaxial connection on the performance of the disc-type UHF sensor with the application of the XFdtd software. The simplified finite-difference time-domain simulation model for the gigahertz transverse electromagnetic (GTEM) cell has been established, and the influence of the coaxial feed position on the performance of the disc-type UHF sensor is studied via the frequency domain effective heights in the simulation. The result shows that as the disc electrode diameter, the thickness, and the dielectric constant of the dielectric substrate increase, the working frequency band shifts toward the reducing direction. The position of the coaxial connection has an obvious effect on the resonant mode of sensor, too.