Azimuth radiation pattern shaping and control for FM broadcast

• Main Authors: Mappatao, Gerino P., Caluyo, Felicito S.
• Format: text
• Published: Animo Repository 2011
• Subjects: FM broadcasting; Antenna radiation patterns; Electrical and Electronics; Systems and Communications
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/1862
• Institution: De La Salle University

FM broadcast stations must transmit power only in areas where the signal is needed. This paper presents a simpler method of shaping the azimuth electric field pattern of an antenna system for FM broadcast applications to exhibit a radiation pattern similar to a directional desired radiation pattern without minor lobes. The method is simpler than the trial-and-error method of adding parasitic elements to achieve a certain desired pattern. It makes use of a uniform linear antenna array composed of two basic antennas or bays with omnidirectional pattern. Radiation patterns are realized by determining the optimum value of the distance between bays and their phase relationship. Genetic Algorithm (GA) is used in determining these optimum values assuring a radiation pattern that resembles the desired pattern. Some GA parameter values fitted for pattern shaping are first determined to improve accuracy and consistency before the GA optimization process is run. Two sample directional patterns are presented to demonstrate the performance of the method. Results show that the proposed method produces near zero cost function values resulting to radiation patterns having very close semblance to the desired pattern. An antenna simulation software is used to validate the results in each sample desired pattern. © 2011 Praise Worthy Prize S.r.l. - All rights reserved.