Measurement and Analysis of Antenna Pattern for MIMO HF Surface Wave Radar

The multiple-input–multiple-output (MIMO) is a popular technology applied in the radar field for its ability to generate virtual elements, which ensures radar miniaturization in the case of obtaining a large array aperture especially for high-frequency surface wave radar. Antenna pattern distortions caused by environmental obstacles seriously contaminate the manifold of MIMO synthesized array, resulting in inaccurate direction-of-arrival (DOA) estimation. In this letter, MIMO antenna patterns including transmitters and receivers are initially measured by shipborne transponder and their effect on static beam patterns are analyzed. The comparison between ideal beam patterns and actual beam patterns reveals that the transmit antenna pattern distortion has an obvious impact on weakening the effect of MIMO synthesized array. Moreover, the experimental results using multiple signal classification algorithm demonstrate that the measured antenna patterns are effective for MIMO DOA estimation improvement.