Title :
Modelling and measurement of high frequency antennas for the U.S. Coast Guard HH-60J helicopter
Author :
Roma Rao, B. ; Jones, D.N. ; Davis, R.J. ; Vessey, R. ; Engbring, T. ; Moseley, Z.V.
Author_Institution :
The MITRE Corp., Bedford, MA, USA
fDate :
June 28 1993-July 2 1993
Abstract :
The authors describe the analysis that was conducted using the NEC3-method of moments code to predict the input impedance and far-field patterns of two types of HF antennas for the US Coast Guard HH-60J helicopter. The operating frequencies for these antennas are 3.123, 5.696 (primary frequency), 8.984 (secondary frequency), 11.201, and 15.084 MHz. The calculated results have been validated by comparison with measurements on the real helicopter as well as on a 1:7.5 scaled down model of the helicopter. The impact of tuning reactance on the radiation efficiency of the antennas, as well as the relative performance of the two antennas for high angle sky wave and ground wave communications over mixed land and sea paths, has been investigated.<>
Keywords :
aircraft communication; antenna radiation patterns; electric impedance; helicopters; loop antennas; method of moments; mobile antennas; monopole antennas; tuning; 11.201 MHz; 15.084 MHz; 3.123 MHz; 5.696 MHz; 8.984 MHz; HF antennas; NEC3-method of moments code; US Coast Guard HH-60J helicopter; communications; far-field patterns; input impedance; measurements; mixed land and sea paths; model; radiation efficiency; shorted loop antenna; tuned monopole antenna; tuning reactance; Antenna measurements; Cable insulation; Coils; Frequency measurement; Helicopters; Impedance measurement; Relays; Sea measurements; Tuning; Wire;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1993. AP-S. Digest
Conference_Location :
Ann Arbor, MI, USA
Print_ISBN :
0-7803-1246-5
DOI :
10.1109/APS.1993.385558
