An aperture-shared multi-port waveguide antenna with multiple feeds is presented in this paper. The antenna consists of sequentially rotated four traditional WR-28 waveguides at 28GHz so as to create a multi-polarized function with decoupling between the ports. In addition, a rectangular DR (Dielectric resonator) is mounted at the center of the four apertures to obtain lower mutual coupling over a wide band and to suppress the cross-polarization in the antenna boresight direction. The proposed antenna achieves high gain of 14.4dBi, low mutual coupling of ≤-20dB on average, sufficient cross-polarization discrimination level at ≃20dB in the 27-29GHz frequency band.

The 5th-generation mobile communication uses multi-element array antennas in not only base stations but also mobile terminals. In order to design multi-element array antennas efficiently, it is important to acquire the characteristics of the direction of arrival (DOA) and direction of departure (DOD), and a highly accurate and simple measurement method is required. This paper proposes a highly accurate and simple method to measure DOA and DOD by applying synthetic aperture (SA) processed at both Rx and Tx sides. It is also shown that the addition of beam scanning to the proposed method can reduce the measurement time while maintaining the peak detection resolution. Moreover, experiments in an anechoic chamber and a shielded room using actual wave sources confirm that DOA and DOD can be detected with high accuracy.

Far-field directivity analysis method where the FDTD method is used to calculate the near-field and then calculating far-field from the near-field has been used practically in wide variety of fields. MR/FDTD method is a simulation method derived from the FDTD method and can provide several advantages to the FDTD method. When combined with the far-field analysis, it theoretically can provide several advantages against the conventional method. In this paper, far-field analysis method that uses MR/FDTD method is introduced and its effectiveness is verified against the conventional method through numerical simulations.