Calibration cell for E-field sensors in water environment

Compact and nonperturbing E-field sensors are used for antenna near field measurements. For application in the research area of hyperthermia these sensors are used in a water environment. Owing to the high dielectric constant of water in the frequency range from DC to /spl sim/1 GHz the sensitivity is changed. To perform a calibration of E-field sensors, a water-filled TEM-cell has been developed. The technique employs a transverse electromagnetic (TEM) transmission cell that operates as a 50 W impedance matched system. A uniform TEM-field is established inside the cell.