Exact Evaluation of a Sommerfeld Integral for the Impedance Half-Plane Problem

임피던스 반 평면에 대한 Sommerfeld 적분의 Closed-Form 계산

  • Koh Il-Suek (The Graduate School of Information Technology and Telecommunication, Inha University)
  • 고일석 (인하대학교 정보통신대학원)
  • Published : 2006.08.01

Abstract

In this paper, a Sommerfeld integral for an impedance half-plane is considered, which is one of classical problems in electromagnetic theory. First, the integral is evaluated into two series representations which are expressed in terms of exponential integral and Lommel function, respectively. Then based on the Lommel function expansion, an exact, closed-form expression of the integral is formulated, written in terms of incomplete Weber integrals. Additionally, based on the exponential integral expansion, an approximate expression of the integral is obtained. Validity of all formulations derived in this paper is demonstrated through comparisons with a numerical integration of the integral for various situations.

본 논문에서는 임피던스 반 평면 문제에서 나오는 Sommerfeld 적분의 closed-form을 계산한다. 우선 주어진 Sommerfeld 적분을 두 개의 급수 형태로 표현한다. 급수 중 하나는 exponential integral로 알려진 초월 함수로, 다른 것은 Lommel 함수로 표현이 된다. Lommel 함수 표현으로부터 주어진 Sommerfeld 적분의 closed-form을 incomplete Weber integral로 표현한다. incomplete Weber integral은 여러 분야에서 사용되고 있고 많은 성질들이 알려져 있다. 또 exponential integral 함수 표현으로부터 Sommerfeld 적분을 incomplete Gamma 함수로 근사화한다. 구한 모든 식들은 수칙 적분 결과와 비교하여 validation을 한다.

Keywords

References

  1. A. Sommerfeld, 'Uber die ausberitung der Wellen in der Drahtlosen telegraphie', Ann. Physik, vol. 28, pp. 665-736, 1909
  2. I. Itoh, Numerical Techniques for Microwave and Millimeter-Wave Passive Structures, Willey & Sons, New York, 1989
  3. A. Banos, Dipole Radiation in the Presence of a Conducting Half-Space, Pegamon, New York, 1966
  4. K. Sarabandi, M. D. Casciato, and I. Koh, 'Efficient calculation of the field of a dipole radiating above an impedance surface', IEEE Trans. on Antenna Propagat., vol. 50, no. 9, pp. 1222-1235, Sep. 2002 https://doi.org/10.1109/TAP.2002.7054733
  5. K. A. Michalski, 'Extrapolation methods for sommerfeld integral tails', IEEE Trans. on Antenna Propagat., vol. 46, no. 10, pp. 1405-1418, Oct. 1998 https://doi.org/10.1109/8.725271
  6. I. V. Lindell, E. Alanen, 'Exact image theory for the sommerfeld half-space problem, Part I: vertical magnetic dipole', IEEE Trans. on Antenna Propagat., vol. AP-32, no. 2, pp. 126-133, Feb. 1984
  7. I. V. Lindell, E. Alanen, 'Exact image theory for the sommerfeld half-space problem, Part II: Vertical electric dipole', IEEE Trans. on Antenna Propagat., vol. AP-32, no. 8, pp. 841-847, Aug. 1984
  8. I. V. Lindell, E. Alanen, 'Exact image theory for the sommerfeld half-space problem, Part III: General formulation', IEEE Trans. on Antenna Propagat., vol. AP-32, no. 10, pp. 1027-1032, Oct. 1984
  9. K. Sarabandi, I. Koh, 'Fast multipole representation of green's function for an impedance half-space', IEEE Trans. on Antenna Propagat., vol. 52, no. 1, pp. 296-301, Jan. 2004 https://doi.org/10.1109/TAP.2003.822440
  10. J. S. Gradshteyn, I. M. Ryzhik, Table of Integrals, Series, and Products, Academic Press, New York, 2000
  11. L. Lewin, Theory of Waveguides, Techniques for the Solution of Waveguide Problems, Wiley and Sons, New York, 1975
  12. M. Abramowitz, I. A. Stegun, Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, Wiley, New York, 1972
  13. M. M. Agrest, M. S. Maksimov, Theory of Incomplete Cylindrical Functions and Their Applications, Springer-Verlag, New York, 1971