Southwest Research Institute® (SwRI®) News

Spherical Dipole Antenna

San Antonio, TX -- Sept. 20, 1984 -- A 30 Hz - 1 MHz spherical dipole probe system for measuring the strength of electric fields, one of a family of electric and magnetic probe systems developed by Southwest Research Institute® (SwRI®) for use in situations demanding minimum field perturbation, has been selected as a winner in the 1984 I-R 100 Competition.

The award, recognizing the development as one of the 100 most significant technological advances of the year, was announced in Chicago by officials of Research & Development magazine, sponsor of the competition.

The new probe, developed for the Motor Vehicle Manufacturer's Association, contains a transmitter which processes the field strength data into a signal that is transmitted to the receiver by way of a fiber optic link, said Melvin J. Johnson, manager for concepts and development in the SwRI Electronic Systems Division.

The system measures the electric field from 1 volt per meter to 30 kV per meter, and has been calibrated at the National Bureau of Standards laboratory in Boulder, Colorado. Its advantages include portability, ease of access to confined spaces, and simplicity in obtaining field strength measurements.

Unlike standards antennas, this and other field measurement systems developed at SwRI are designed for minimum field perturbation through the use of miniaturization, special shapes, and nonperturbing data and control links. These unusual design features also allow the probes to be placed in close proximity to an object, or inside equipment, such as an automobile or a computer, to measure internal field strengths.

In addition to Johnson, developers of the probe are E.H. Cooper, Jr., senior research engineer, and Homi Gorakhpurwalla, formerly an engineer on the Institute staff and currently a member of the engineering faculty of Texas A&I University, Kingsville, Texas.

Southwest Research Institute is an independent, not-for-profit organization headquartered in San Antonio, with a staff of more than 2000 engaged in applied research and development in many areas of science and engineering.

For more information about the Spherical Dipole Antenna, contact Joe Fohn, Communications Department, Southwest Research Institute, P.O. Drawer 28510, San Antonio, Texas, 78228-0510, Phone (210) 522-4630, Fax (210) 522-3547.

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