RECEPTION AND TRANSMISSION OF TRANSIENT ELECTROMAGNETIC FIELDS.
Abstract
The receiving and transmitting properties of small linear antennas, conical antennas, and loops for transient electromagnetic fields were investigated experimentally. Short electrical dipoles loaded by a capacitance represented by a cathode follower can be used successfully for the measurement of transient fields with rise times of less than 1 nanosecond, if the first antenna resonance is suppressed by a series resistor at the base of the antenna. The currents induced on nonresonant structures by transient electromagnetic fields are investigated and their application to a direct measurement of the time sequence of the electromagnetic field is discussed. Signals with a simple and known time dependence such as a unidirectional pulse can be radiated into space if the reflection of current waves at discontinuities of the antenna structure is avoided. In a manner similar to that useful for the absorption of continuous waves in media with a stratified conductivity, it is shown that reflections at discontinuities can be avoided by dipoles with tapered resistive loading. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 13, 1964
- Accession Number
- AD0600535
Entities
People
- Hans J. Schmitt
Organizations
- Harvard University