Accession Number : AD0287035

Title :   A PHOTOCONDUCTIVE PROBE FOR MEASURING ELECTROMAGNETIC FIELDS

Corporate Author : HARVARD UNIV CAMBRIDGE MASS CRUFT LAB

Personal Author(s) : IIZUKA,KEIGO

Report Date : 25 JUL 1962

Pagination or Media Count : 19

Abstract : Probes were constructed for measuring the intensity of the electromagnetic field in which the usual connecting leads between the probe and the detector are eliminated. The new devices are modulated reradiating or scattering antennas that consist of either a small dipole (for measuring E) or a small shielded loop (for measuring H) center-loaded with a photo cell illuminated by a chopped beam of light. The modulated scattered signal from the probe is proportional to either the component of the E field which is parallel to the axis of the dipole, or to the component of the H field which is perpendicular to the plane of the shielded loop. The scattered signal is received by an additional antenna or by the same antenna as is used for transmission. The received signal is amplified by a lock-in amplifier. The same principle was applied to the measurement of the distribution of current along an antenna with arbitrary shape. (Author)

Descriptors :   *ANTENNA RADIATION PATTERNS, *ELECTROMAGNETIC FIELDS, *MAGNETS, *PHOTOELECTRIC CELLS (SEMICONDUCTOR), *PHOTOTUBES, DIPOLE ANTENNAS, INSTRUMENTATION

Distribution Statement : APPROVED FOR PUBLIC RELEASE