Design of an asymmetric parabolic cylinder antenna with high aperture efficiency

With respect to the asymmetric cylindrical parabola antenna constructed for radio astronomical observation at 327 MHz, the design method and the verification of the design values are reported. The present antenna placed emphasis on the improvement of the receiving sensitivity and is designed to increase the aperture efficiency as much as possible. To carry out an optimum design of the primary feed made of a dipole array with a corner reflector, the structural parameters of the primary feed have been studied. It was found that there exist optimum values. The reduction of the efficiency due to the transmission loss and the phase error loss of the reflector surface made of stainless wires was derived. The overall aperture efficiency was estimated to be 75.9 percent. In an actually constructed antenna, the aperture efficiency measured with a celestial radio source as the standard radio source was 71 ± 5 percent. It was confirmed that the aperture efficiency derived from the computation and the optimum design values are reasonable.