TY - GEN
T1 - Analysis of HF antennas on a helicopter in the presence of a stratified ground
AU - Han, Dong Ho
AU - Polycarpou, Anastasis C.
AU - Balanis, Constantine A.
PY - 1999
Y1 - 1999
N2 - Analysis of antennas on a helicopter airframe including the surrounding environment, such as the ground, will provide much more reliable radiation characteristics for communication link budget predictions. In order to account for all reflections and diffractions from the airframe, as well as those from a stratified ground, a full-wave analysis should be used. Since the exact Green's function for a stratified ground is available, the radiation problem of a helicopter above the ground reduces to a problem of finding the total equivalent source in the presence of the ground. In this paper, HF antennas, such as a 14-ft towel-bar and a 24-ft inverted-L on the AH-64 (Apache) full-scale helicopter, are analyzed in the presence of a stratified ground. In particular, the ground influence on the radiation pattern is investigated using the finite element method (FEM) in conjunction with Norton's approximation. Therefore, the radiated field contains not only the space wave but also the surface wave which is important for a short observation distance. The lossy ground is defined by its relative permittivity and electric conductivity.
AB - Analysis of antennas on a helicopter airframe including the surrounding environment, such as the ground, will provide much more reliable radiation characteristics for communication link budget predictions. In order to account for all reflections and diffractions from the airframe, as well as those from a stratified ground, a full-wave analysis should be used. Since the exact Green's function for a stratified ground is available, the radiation problem of a helicopter above the ground reduces to a problem of finding the total equivalent source in the presence of the ground. In this paper, HF antennas, such as a 14-ft towel-bar and a 24-ft inverted-L on the AH-64 (Apache) full-scale helicopter, are analyzed in the presence of a stratified ground. In particular, the ground influence on the radiation pattern is investigated using the finite element method (FEM) in conjunction with Norton's approximation. Therefore, the radiated field contains not only the space wave but also the surface wave which is important for a short observation distance. The lossy ground is defined by its relative permittivity and electric conductivity.
UR - http://www.scopus.com/inward/record.url?scp=85039984239&partnerID=8YFLogxK
U2 - 10.1109/APS.1999.789186
DO - 10.1109/APS.1999.789186
M3 - Conference contribution
AN - SCOPUS:85039984239
T3 - IEEE Antennas and Propagation Society International Symposium: Wireless Technologies and Information Networks, APS 1999 - Held in conjunction with USNC/URSI National Radio Science Meeting
SP - 496
EP - 499
BT - IEEE Antennas and Propagation Society International Symposium
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 1999 IEEE Antennas and Propagation Society International Symposium, APSURSI 1999
Y2 - 11 July 1999 through 16 July 1999
ER -