A Source of E and H Fields for Antenna-Factor Calibration

The loop cell used for calibration is fabricated using two intersecting metal sheets joined at the intersection and forming a 360 angle. A section of a loop is mounted between two coaxial panel jacks, one on each sheet located at a distance equal to the loop radius from the intersection. A known current through this section of electrically small loop produces calculable E and H fields between the sheets in the plane of the loop. These known fields may be used to determine the antenna factor of small E and H antennas placed in the field if the mutual impedance due to the antenna images in the sheets is negligible and the antenna is not close to the open edges of the cell. Measured and calculated antenna factors agree within ± 2 dB between 0.25 and 1000 MHz.