Frequency shifting of reflection coefficient minimum point in antenna array

Ferdinand Vavrík – Jozef Hallon

   The paper present study of frequency shift of the minimum reflection coefficient point in relation to the antenna spacing in linear and circular antenna arrays. The spacing of CB-band monopole antenna was in the range of 0.015 to 0.12 multiples of the antenna working wavelength. Number of elements in the antenna arrays ranged from two to four. The minimum reflection coefficient positions on frequency scale were obtained by several series of experiments inside an anechoic chamber and confirmed by simulations. The research showed two facts. First, mutual impedance has the biggest impact when antenna spacing is in the range of reactive near field region. Second, circular antenna arrays are better choice in applications for a small number of antennas with antenna spacing in the range of reactive near field region.

Keywords: antenna array, reflection coefficient, mutual impedance

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