Improvement of Angular Dependence of Angular Profile in DOA Measurement Method using Rotating Reflector Antenna

In next-generation mobile communications, the proactive use of millimeter-wave and terahertz-wave frequencies, which can secure a wide frequency bandwidth, is anticipated. The authors reported a measurement method using a rotating reflector antenna to realize high-speed direction-of-arrival (DOA) measurement by rotating a large-aperture antenna at these frequencies. The authors previous method adopted a circularly polarized antenna as the primary radiator to accommodate the polarization rotation of the antenna. However, this method had the issue of angular dependence in the angular profile. To solve this problem, this paper proposes a measurement method that uses an orthogonally polarized antenna as the primary radiator of a rotating reflector antenna for rotational measurements, and processes the acquired data offline. To confirm the effectiveness of the proposed method, a demonstration experiment is conducted in an anechoic chamber, and it is shown that an angular profile with less angular dependence can be obtained than using a circularly polarized antenna as the primary radiator. We also show that the proposed method is capable of fast DOA measurement.