Characteristics of a single element dipole and array of dipoles at frequencies of selected TV stations in Nigeria

Abstract

Based on the computations arising from the formulation, this paper investigates the characteristics of dipoles. The problem is two-fold: First, is how a single element dipole radiates at frequencies of selected TV (Television) stations in Nigeria. Second, is the implication for array of dipoles at the aforementioned frequencies. The four frequencies of interest are those of NTA (Nigerian Television Authority) New Bussa, Niger State (470MHz), NTA channel 43, Abakaliki, EbonyiState (647.25MHz), NTA Oshogbo, Osun State (702.25MHz) and NTA Ijebu Ode, Ogun State (814.25MHz). The results are presented in three modes: First, are the graphical profiles of fields radiated by a single element dipole for all the TV stations. Second, are the patterns displayed for array of dipoles for the stations. Lastly, the normalized array factor profiles are also shown for the array of dipoles. The results obtained show that NTA Oshogbo covers more area in terms of the enhanced isotropic radiator viewed from its isometric plot than the other three TV Stations but suffers 11.58%degradation in sidelobe strength relative to the main beam radiated. The results also show that if a single dipole is used for the four NTA stations, there will be 58.62% degradation in the sidelobe strength of NTA Ijebu Odewhich can be reduced to 20% if a line ararray of 16-element dipole is used.