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A measurement method of an active element antenna pattern in a hybrid antenna array with heterodyne architecture under a real environment is proposed and applied to the design of an ultralow sidelobe level scanning array. To avoid the phase uncertainty caused by the local oscillator signal in the heterodyne architecture, a phase‐normalized active element pattern (PNAEP) is used to characterize the element antenna patterns of both amplitude and phase. The PNAEP has almost taken account of all the practical factors of an array, such as mutual couplings, various types of element antennas, unequal spacing, or diverse environmental effects. The PNAEP is measured with a 16‐element scanning receiving array with a heterodyne architecture to validate the feasibility of the PNAEP. Based on the PNAEP, the scanning array achieve an ultralow sidelobe level of −33 dB. Applying to various receiving array architectures the PNAEP method is a feasible and universal tool for array synthesis and optimization under real environments. [ABSTRACT FROM AUTHOR]

A metasurface lens antenna fed by a planar $8\times8$ dual polarized antenna array is proposed and characterized for full-dimensional massive multiple-input multiple-output (MIMO) and multibeam systems at sub-6 GHz bands. The lightweight multilayer metasurface structure consisting of Jerusalem cross elements is used for a planar lens design. The lens antenna with the size of $10\lambda _{0} \times 10\lambda _{0} \times 5\lambda _{0}$ is fed by an $8\times8$ dual-polarized stacked patch array to operate over the range from 5.17 to 6.10 GHz, where $\lambda _{0}$ is the free-space operating wavelength at the center frequency of 5.6 GHz. This article shows the scanning range of ±25° with a maximum gain of 22.4 dBi and the gain variation of 3.3 dB at 5.6 GHz. Beam coverage performance, pattern envelope correlation coefficient, and port isolation properties demonstrate its full-dimension access capability of the antenna. Besides, the multibeam antenna system with high-gain coverage is achieved by beams operating at the same frequencies, while the frequency division multiplexing can be realized for the isolated beams. The proposed metasurface lens antenna, featuring lightweight, compactness, and low cost compared to a 3-D dielectric lens and low-complexity compared to the array scenarios, can be an alternative for fifth-generation (5G) sub-6 GHz frequency bands. [ABSTRACT FROM AUTHOR]

This study presents a hybrid receiving array architecture that combines analog and digital beamforming to offer a solution for the phased-array feed and other multifunction receive-only applications. This architecture is capable of handling multiple beams forming simultaneous and precision beam steering. To further reduce the hardware counts of the online performance monitoring, a calibration method is proposed in which none of the transmitters or the dedicated distribution network are used. The hybrid architecture concept and built-in calibration are validated experimentally via a prototype. The system performance, including the statistical results of the baseband measurement, phase error, and radiation patterns under various array configurations, are illustrated. An effective phase tuning step of 0.1^\circ, as well as a steering resolution at the subdegree level, is achieved, and the measured aperture distribution is in good agreement with that derived from the proposed online calibration. [ABSTRACT FROM PUBLISHER]