In this study, the impact of finite ground plane edge diffractions on the amplitude patterns of aperture antennas is examined. The Uniform Theory of Diffraction (UTD) and the Geometrical Optics (GO) methods are utilized to calculate the amplitude patterns of a conical horn, and rectangular and circular waveguide apertures mounted on square and circular finite ground planes. The electric field distribution over the antenna aperture is obtained by a modal method, and then it is employed to calculate the geometrical optics field using the aperture integration method. The UTD is then applied to evaluate the diffraction from the ground planes' edges. Far-zone amplitude patterns in the E and H planes are finally obtained by the vectorial summation of the GO and UTD fields. In this paper, to accurately predict the H-plane amplitude patterns of circular and rectangular apertures mounted on square ground plane, the E-plane edge diffractions need to be included because the E-plane edge diffractions are much more intensive than those of the H-plane edge regular and slope diffractions. Validity of the analysis is established by satisfactory agreement between the predicted and measured data and those simulated by Ansoft's High Frequency Structure Simulator (HFSS). Good agreement is observed for all cases considered.
2. Kraus, J. D. and R. J. Marhefka, Antennas for All Applications, McGraw-Hill, New York, 2002.
3. , , , Online Available: http://www.ansoft.com/products/hf/hfss/Ansoft Corporation HFSS.
4. Balanis, C. A., Advanced Engineering Electromagnetics, John Wiley and Sons, New Jersey, 2012.
5. Aboserwal, N. A., C. A. Balanis, and C. R. Birtcher, "Conical horn: Gain and amplitude patterns," IEEE Trans. Antennas Propagat., Vol. 61, No. 7, 3427-3433, Jul. 2013.
6. Love, A. W., Electromagnetic Horn Antennas, IEEE Press, New York, 1976.
7. Keller, J. B., "Geometrical theory of diffraction ," J. Opt. Soc. Amer., Vol. 52, 116-130, Feb. 1962.
8. Kouyoumjian, R. G. and P. H. Pathak, "A uniform geometrical theory of diffraction for an edge in a perfectly conducting surface," Proceedings IEEE, Vol. 62, No. 11, 1448-1461, Nov. 1974.
9. Ibrahim, H. M. and D. T. Stephenson, "Radiation patterns of a λ/4 monopole mounted on thick finite square and circular ground planes," Int. J. Electronics, Vol. 64, No. 3, 345-358, Jul. 1988.
10. Huang, J., "The finite ground plane effect on the microstrip antenna radiation patterns," IEEE Trans. Antennas Propagat., Vol. 31, No. 4, 649-653, Jul. 1983.
11. Narasimhan, M. S. and M. Sheshadri, "GTD analysis of the radiation patterns of conical horns," IEEE Trans. Antennas Propagat, Vol. 26, No. 6, 774-778, Nov. 1978.
12. Ali, M., S. Sanyal, and S. Park, "Analysis of horn radiation pattern using UTD edge and corner diffraction," Progress In Electromagnetics Research M, Vol. 17, 87-99, 2011.
13. Menendez, R. and S. W. Lee, "Analysis of rectangular horn antennas via uniform asymptotic theory," IEEE Trans. Antennas Propagat., Vol. 30, No. 2, 241-250.
14. Narsimhan, M. S. and S. K. Rao, "GTD analysis of the near-field patterns of pyramidal horns," Proceedings IEEE, Vol. 126, No. 12, 1223-1226, Dec. 1979.
15. Balanis, C. A., "Pattern distortion due to edge diffractions," IEEE Trans. Antennas Propagat., Vol. 18, 561-563, Jul. 1970.
16. Ali, M. and S. Sanyal, "A finite edge GTD analysis of the H-plane horn radiation pattern," Proceedings IEEE, Vol. 58, No. 3, 969-973, Mar. 2010.
17. Yu, J. S. and R. C. Rudduck, "H-plane pattern of a pyramidal horn," IEEE Trans. Antennas Propagat., Vol. 17, No. 5, 651-652, Sep. 1969.
18. Yu, J. S., R. C. Rudduck, and L. Peters, "Comprehensive analysis for E-plane of horn antennas by edge diffraction theory," IEEE Trans. Antennas Propagat., Vol. 14, No. 2, 138-149, Mar. 1966.
19. Russo, P. M., R. C. Rudduck, and L. Peters, "A method for omputing E-plane patterns of horn antennas," IEEE Trans. Antennas Propagat., Vol. 13, No. 2, 219-224, Mar. 1965.
20. Balanis, C. A., "Radiation from conical surfaces used for high-speed spacecraft," Radio Science, Vol. 7, No. 2, 339-343, Feb. 1972.
21. Ryan, C. and L. Peters, "Evaluation of edge-diffracted fields including equivalent currents for the caustic regions," IEEE Trans. Antennas Propagat., Vol. 17, No. 3, 292-298, May 1969.