Ground effects for VHF/HF antennas on helicopter airframes

Dong Ho Han, Anastasis C. Polycarpou, Constantine Balanis

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

In this paper, the finite element method (FEM) is used to predict the space and surface wave radiation patterns of VHF/HF antennas mounted on a helicopter in the presence of a lossy ground. The equivalent sources of the radiation system are obtained by solving an FEM problem in conjunction with an absorbing boundary condition (ABC) or an impedance boundary condition (IBC). From the equivalent sources, the total radiated field is calculated using the equivalence principle and superposition; the original problem is converted into a set of properly combined Hertzian dipoles referred to as the Sommerfeld problem. Instead of evaluating the Sommerfeld integral rigorously, Norton's approximation is used to improve the overall computational efficiency. The validation of this method is accomplished in two steps: first, the FEM is compared with the finite-difference time-domain method (FDTD) in the absence of a lossy ground; second, the Hertzian dipole problem is solved in the presence of a lossy ground and the results are compared with analytic solutions. Finally, this technique is extended to analyze an antenna on a helicopter above a lossy ground.

Original languageEnglish (US)
Pages (from-to)402-412
Number of pages11
JournalIEEE Transactions on Antennas and Propagation
Volume49
Issue number3
DOIs
StatePublished - Mar 2001

Fingerprint

Ground effect
Airframes
Helicopters
Antennas
Finite element method
Boundary conditions
Antenna grounds
Finite difference time domain method
Directional patterns (antenna)
Computational efficiency
Surface waves
Radiation

Keywords

  • Ground effects
  • Helicopter airframe
  • HF/VHF antennas

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Computer Networks and Communications

Cite this

Ground effects for VHF/HF antennas on helicopter airframes. / Han, Dong Ho; Polycarpou, Anastasis C.; Balanis, Constantine.

In: IEEE Transactions on Antennas and Propagation, Vol. 49, No. 3, 03.2001, p. 402-412.

Research output: Contribution to journalArticle

Han, Dong Ho ; Polycarpou, Anastasis C. ; Balanis, Constantine. / Ground effects for VHF/HF antennas on helicopter airframes. In: IEEE Transactions on Antennas and Propagation. 2001 ; Vol. 49, No. 3. pp. 402-412.
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