TY - GEN
T1 - Finite element analysis of VHF/UHF antennas on helicopter airframes
AU - Han, Dong Ho
AU - Polycarpou, Anastasis C.
AU - Balanis, Constantine
N1 - Publisher Copyright:
© 1998 IEEE.
PY - 1998
Y1 - 1998
N2 - In VHF and UHF bands, antenna patterns for short range airborne communications are required to be omni-directional. Contributions from reflections and diffractions from the airframe usually distort the primary radiation patterns of antennas mounted on airframes. Moreover, these diffractions and reflections become increasingly important as the frequency of operation increases. Therefore, for this type of application, an antenna performance simulated without the airframe is not an accurate representation. In this study, an accurate and versatile finite element method (FEM) based on the discretization of Helmholtz's equation has been developed to analyze VHF and UHF antennas mounted on helicopter airframes, parts of which may include composite material and anisotropies. The FEM code was implemented with linear edge-based tetrahedral elements and first/second-order Absorbing Boundary Conditions. Possible material anisotropies in the computational domain are accounted for by using a permittivity and a permeability tensor. Radiation characteristics are predicted for absolute gain, spatial field distribution, input impedance and return loss, and then compared with measurements for verification.
AB - In VHF and UHF bands, antenna patterns for short range airborne communications are required to be omni-directional. Contributions from reflections and diffractions from the airframe usually distort the primary radiation patterns of antennas mounted on airframes. Moreover, these diffractions and reflections become increasingly important as the frequency of operation increases. Therefore, for this type of application, an antenna performance simulated without the airframe is not an accurate representation. In this study, an accurate and versatile finite element method (FEM) based on the discretization of Helmholtz's equation has been developed to analyze VHF and UHF antennas mounted on helicopter airframes, parts of which may include composite material and anisotropies. The FEM code was implemented with linear edge-based tetrahedral elements and first/second-order Absorbing Boundary Conditions. Possible material anisotropies in the computational domain are accounted for by using a permittivity and a permeability tensor. Radiation characteristics are predicted for absolute gain, spatial field distribution, input impedance and return loss, and then compared with measurements for verification.
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U2 - 10.1109/APS.1998.699123
DO - 10.1109/APS.1998.699123
M3 - Conference contribution
AN - SCOPUS:0031641033
SN - 0780344782
SN - 9780780344785
T3 - IEEE Antennas and Propagation Society International Symposium, 1998 Digest - Antennas: Gateways to the Global Network - Held in conjunction with: USNC/URSI National Radio Science Meeting
SP - 248
EP - 251
BT - IEEE Antennas and Propagation Society International Symposium, 1998 Digest - Antennas
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 1998 IEEE Antennas and Propagation Society International Symposium, APSURSI 1998
Y2 - 21 June 1998 through 26 June 1998
ER -