Improvement of the mutual coupling effect between biconical antenna and antenna mast

It is well known that mutual coupling effect and problems exist between transmitting and receiving antennas. One factor is the coupling effect between antennas and masts. It can be more than 1 dB for omni-directional antennas with vertical polarization. This effect can be improved by utilizing the average method of changing distance between antennas and antenna mast. According to the reference site method (RSM) proposed in the CISPR 16-1-4-2012, a comparison test is made between the Bureau of Standards, Metrology & Inspection (BSMI), Taiwan and the National Institute of Metrology (NIM), China. The RSM and geometrical specific correction factor from the Annex G & H of ANSI C 63.5-2006 was also introduced into this comparison. It shows that the average method can improve the effect of mutual coupling between antennas and masts to 0.5 dB. This case study will discuss the theory of the average method and the measured result. The result will help to improve the measurement uncertainty for the validation of semi-anechoic chambers.