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In this article, the 3D‐printed dielectric lens is proposed to generate Bessel beam in millimeter‐wave band. The dielectric lens is made of many square unit cells with the side length of a half wavelength. The unit cells with different thicknesses generate different insertion phase shift to the transmitted millimeter wave. The insertion phase distribution of the lens is calculated by comparing the phase distributions of the incident Gaussian beam and the desired output Bessel beam. Three types of lenses are simulated and fabricated using 3D printing technology with Nylon. The measured magnitude and phase distributions of zero‐order Bessel beam agree with the simulated results very well and the measured phase distributions of the first‐order Bessel beam carry orbital angular momentum. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, two novel kinds of focusing elements as reflectors are analyzed and compared. One is the grooved Fresnel zone plate reflector with continuous phase-correcting. The other called subzone paraboloid reflector, has the profile that consists of a series of paraboloids. Their diffraction efficiencies and bandwidths are described. The two elements still preserve the advantages of Fresnel zone plates, namely, low profile, high efficiency, and simple fabrication. Two dual-reflector antennas using the proposed focusing elements as the main reflectors are simulated and the results show that these antennas have good radiation performances. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:101-108, 2015. [ABSTRACT FROM AUTHOR]