VHF and UHF poly-directional transmit aerial - uses on sides of the support tower symmetrical central arranged and mirror-image positioned radiators

摘要

The transmit aerial for VHF/UHF frequencies consists of several radiator groups held in a mainly vertical position by a tower structure which has these radiator groups arranged symmetrical and central with regard to the structure sides. The radiator elements or groups in equal horizontal planes are fed in phase while the amplitude distribution in the vertical planes is varying. The radiator elements or groups which in the horizontal plane from a mirror image to each other are fed with a phase shift of 90 deg. between each other. The aerial thus seems divided into two parts each of which radiates the same fraction of the total energy. The radiator groups may be arranged in the form of a pine tree array or for polydirectional use.