S. V. Ermolaev - Leading Engineer in Radio Communications, FSUE Radio Research and Development Institute (NIIR) E-mail: ermo-laev@niir.ru

The paper [1] gives an example of calculation for dual-reflector antenna with the offset feeder and elliptical aperture, using geometrical optics approximation. As in the case of circular aperture, the calculation for the reflector surfaces in the paper is reduced to numerical solution of differential equation with partial derivatives of second order that poses some problems. The paper [2] represents reflector and convergent reflector surfaces as the Zernike polynomial series. Coefficients of those polynomials are calculated by substituting them into equations obtained in [1] and by solving the corresponding systems of linear equations. The paper [3] has solved this task using the optic ray tracing method which is detailed in [4]. For the calculation of the reflector and convergent reflector surfaces, the paper proposes a method using numerical integration of equations obtained in [5, 6], which calculates their profiles with sufficient practical accuracy. The paper provides necessary equations allowing calculation of the reflector surfaces of dual-reflector antenna with the offset feeder and elliptical aperture, and an example of the calculation. It has been shown that the proposed method allows for calculation of the reflector and convergent reflector surfaces providing good antenna electrodynamic characteristics comparable to those of antenna with a circular aperture.

 

1. Westcott B.S., Graham R.K., Brickell F. Systematic design of a dual offset reflector antenna with an elliptical aperture // IEE Proc. Dec. 1984. V. 131. № 6. P. 365-370.
2. Viskum H-H., Wolf H. A dual offset shaped reflector for elliptical beams // Eighth Internat. Conf. on Antennas and Propagation. 1993. V. 1. P. 565-569.
3. Kildal P.-S. Laws of geometrical optics mapping in multi-reflector antennas with application to elliptical apertures // IEE Proc. Dec. 1989. V. 136. № 6. P. 445-453.
4. Kildal P.-S. Synthesis of multireflector antennas by kinematic and dynamic ray tracing // IEEE Trans. on AP. Oct. 1990. V. 38. № 10. P. 1587-1599.
5. Ermolaev S.V. Raschjot dvukhzerkalnykh antenn s vynesennym obluchatelem s ispolzovaniem kompleksnykh koordinat // Trudy NIIR. 2014. № 2. S. 43-50.
6. Ermolaev S.V. Sintez dvukhzerkalnykh antenn s vynesennym obluchatelem i kruglojj aperturojj // Antenny. 2014. № 7. S. 11-15.
7. Ermolaev S.V. Krosspoljarizacija dvukhzerkalnojj antenny s vynesennym obluchatelem // Antenny. 2014.№ 6. S. 3-7.
8. Clarricoats P.J.B., Saha P.K. Propagation and radiation behavior of corrugated feeds. Part 2 - Corrugated-conical-horn feed // IEE Proc. Sept. 1971. V. 118. № 9. P. 1177-1186.