Accession Number:

ADA167037

Title:

A Method of Predicting the Field Radiated by a Pulse Driven Antenna

Descriptive Note:

Corporate Author:

HARRY DIAMOND LABS ADELPHI MD

Report Date:

1986-07-01

Pagination or Media Count:

13.0

Abstract:

The radiated free field from a pulse-driven antenna is normally recorded as a waveform, with the peak amplitude then being compared to a calculated value. Performing the calculation requires knowing the variables of antenna impedance, applied peak voltage, and the distance from the antenna to the measurement point. A possible source of error for this calculation is the antenna impedance value, which varies as a function of the antenna geometry and length. A minicomputer, controlling a digital processing oscilloscope, is used to apply the measurement techniques of time-domain sampling, signal averaging, and time shifting, resulting in a waveform which is representative of the antenna feed point impedance as a function of geometry and length. By also measuring and recording the time-domain variations of the pulse applied to the antenna, one can predict the radiated non-ground-reacted field as a function of time by substituting the impedance and pulse-applied waveforms in the formula and performing the calculations for each instant in time with the computer. The predicted and measured fields are found to be in good agreement.

Subject Categories:

  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE