Broadband isotropic probe system for simultaneous measurement of complex E- and H-fields

US4588993A · kind A · utility

Assignee

• The United States of America as Represented by the Secretary of the Department of Health and Human Services · US

Inventors

• Tadeusz M. Babij · Jacksonville, US
• Howard Bassen · Bethesda, US

Key dates

• Filing date: May 19, 1983
• Grant date: May 13, 1986
• Expiry date: May 19, 2003

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01Q21/28
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A broadband isotropic probe system simultaneously measuring the E- and H-field intensities of rf complex, near-field electromagnetic radiation comprises a set of three mutually orthogonal dipole antennas and a set of three mutually orthogonal loop antennas located within the same volume of space. Each antenna has associated circuitry comprising a frequency-response-shaping filter and diode detector to provide a frequency response which is flat over the desired frequency bandwidth. The lengths of the dipoles are kept electrically small so that the EM fields are not perturbed. The diameters of the loops are kept electrically small so that the E-field pickup will be negligible. Coupling between any of the probe's antennas is also minimized by the use of electrically small antennas. Circuit means based on the use of square law detectors is also provided, the circuit including an arrangement of analog or digital data processing portions leading into a display means and a data recorder.