Calibration With a Monocone on a Ground Plane

摘要

Calibration with a monocone on a ground plane (CALMOPLA) is a tool for the calibration of low-sensitivity and ultrawideband (UWB) electric or magnetic field probes. It consists of a small conical monopole (D-dot), positioned in the center of a ground plane and emitting electromagnetic waves. Close to the reference plane, the radiated signals are quasi-spherical waves which can be described by well-known analytical expressions. The originality of the CALMOPLA calibration method consists in radiating at once spherical waves at UWB frequencies (from several tens of megahertz to several gigahertz) with a unique emitter, in free-field (377- impedance), in delivering a signal amplitude usable for low-sensitivity sensor calibration, and this with reasonable geometrical dimensions. A vector network analyzer is sufficient to cover the frequency range of most of the sensors to be calibrated. Nevertheless, the use of a low-noise amplifier and a low-frequency power amplifier allows the measurement range to be extended to a very low-sensitivity sensor anywhere on CALMOPLA.