Three-Dimensional Radiation Characteristics of a Pyramidal Horn-Reflector Antenna

Since its conception in the late forties1 and its implementation in the fifties,2,3 thousands of pyramidal horn-reflector antennas have been installed in terrestrial radio systems. The antenna is a broadband device currently used in the 2-, 4-, 6-, and 11-GHz common-carrier bands. Antenna dimensions are given in Fig. 1, along with coordinates as used below. Discussion of its performance will be limited in this paper to the 4- and 6-GHz bands which constitute the major usage. Although the performance of this antenna is well known in the xz and in the yz planes (see Fig. 1), its exact performance in directions other than these principal planes was unknown until the measurements reported here were made. The three-dimensional responses are of interest in any case where an interfering signal impinges upon the antenna outside of these planes, e.g., direct interference from other terrestrial stations or satellites, or reflections from buildings or the ground.4 Calculated three-dimensional responses based on aperture fields have been reported for small angles from the main beam.5 Here, we also include calculated three-dimensional responses for the 4-GHz band out to angles of 30° from the main beam. 913