Directive Gain of a $4\times 4$ Phased Array Using Printed Yagi-Uda Type Elemnts

To compensate for spatial attenuation in sub- THz (300 GHz) band communications, gain enhancement using a phased array was investigated. In order to suppress grating lobes during 30° beam tilting, the array element spacing must be less than one wavelength (1 mm). A printed Yagi-Uda type antenna element proposed by the authors has a gain of 7.5 dBi in the lateral direction of the substrate, which is close to the gain of the waveguide aperture. In this paper, directive gain of a 4×4 printed Yagi-Uda type antenna arrays was analyzed. The gain of 19.7 dBi was obtained, and it was not deteriorated even when the beam was tilted by 30°. This is because the directivity of a single element has a low gain in the grating lobe direction.