Title :
Optimized tapered resistivity profiles for wideband HF monopole antenna
Author_Institution :
MITRE Corp., Bedford, MA, USA
Abstract :
The author reports on theoretical investigations conducted to optimize the resistivity taper for improving the efficiency of the wideband HF monopole antenna. Particular attention is given to making improvements at the lower frequencies, without seriously compromising the radiation pattern and impedance-matching requirements over the 5-30 MHz frequency band. Antenna characteristics such as the input impedance, efficiency radiation pattern, and current distribution for various resistivity taper profiles have been calculated using the NEC-3 method-of-moments code. The effects of the lossy earth and a finite-size radial-wire ground screen on the antenna performance have also been analyzed. Results indicate that large improvements in antenna efficiency across the entire 5-30 MHz band can be obtained by a suitable modification of the original Wu-King resistivity (1965) taper profile.<>
Keywords :
antenna radiation patterns; antenna theory; current distribution; electric impedance; 5 to 30 MHz; NEC-3 method-of-moments code; antenna efficiency; antenna performance; current distribution; finite-size radial-wire ground screen; impedance-matching; input impedance; lossy earth; lower frequencies; radiation pattern; resistivity taper optimization; resistivity taper profiles; tapered resistivity profiles; theoretical investigations; wideband HF monopole antenna; Antenna radiation patterns; Antenna theory; Broadband antennas; Conductivity; Current distribution; Frequency; Hafnium; Impedance; Moment methods; Wideband;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1991. AP-S. Digest
Conference_Location :
London, Ontario, Canada
Print_ISBN :
0-7803-0144-7
DOI :
10.1109/APS.1991.174938
