Some preliminary results of radiation pattern measurements for a vertical dipole over sea

摘要

Radiation pattern of a commonly used vertical half-wave dipole was measured over sea. A compact setup was designed and produced based on a shallow pool filled with sea water, defining the propagation path entirely over sea. Antenna under test transmitted a wave across the pool towards the receiving antenna that measured the field strength in various positions, to obtain the radiation pattern of the transmitting antenna over sea. Due to constrictions in the setup dimensions, the working frequency was chosen in GHz range, namely 2.48 GHz. The results are however scalable to lower frequencies. The patterns obtained by preliminary measurements for vertical dipole raised by 1λ and 2λ above sea surface are in good accordance with the patterns obtained by NEC simulation.