Directivity Measurement of Circular Phased Array 4 × 4 MIMO Antenna

This is the authors' abstract. We don't add key points for this paper.

We are currently developing a 4 × 4 MIMO antenna system that utilizes a circular phased array technology for ad hoc connected car systems. In this study, we measure the directivity of the proposed antenna when the optimum weight functions are realized. An attenuator and a microstrip circuit are used to represent the optimum weight function and the phase shift value, respectively. Then, a calibration of the system is necessary owing to the power loss occurred in the RF controlled part. The results show that a good agreement between the measured results and the analytical outcome can be observed, indicating that the weight function and the phase shift value work well according to the angle of the incident wave.