Empirical Measurements of Antenna Polarization Mismatch and Misalignment Due to Angular Motion

Propagation in maritime environment dynamically change due to the direct impact of ocean wave undulation to the antenna position and orientation. This paper presents an approach in characterizing signal propagation in a maritime environment by replicating ocean wave-induced antenna motions in a semi-anechoic chamber. The proposed setup may also be used to test mismatch and misalignment mitigating techniques in a controlled environment. The effect on the received signal power of angular motions such as roll, and pitch due to ocean wave undulation, which causes polarization mismatch and antenna misalignment, were investigated in this study. Different setup configurations were applied by varying the tilting orientation, tilting period and tilting range of the antenna in order to replicate various sea state conditions. Measurements reveal the extent of signal degradation due to polarization mismatch and antenna misalignment, and how received signal power degrades with the tilting range. Signal power deviation was measured to reach up to 3 dB and signal power was measured to swing up to 10dB.