A mm-Wave Phased-Array Fed Torus Reflector Antenna With ±30° Scan Range for Massive-MIMO Base-Station Applications
Amr Elsakka, Amirashkan Farsaei, A.J. van den Biggelaar, Ad C. F. Reniers, Martin Johansson, Rob Maaskant, Ulf Johannsen, Oleg Iupikov, A.B. Smolders, Marianna Ivashina
Abstract
A phased-array fed reflector antenna system is presented which can be used for mm-wave base station applications. The proposed system is designed to support massive-multi-input–multi-output (MIMO) scenarios within a wide coverage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pm 30^\circ $ </tex-math></inline-formula> ) in the azimuth plane and a limited coverage at the elevation plane. A design and characterization methodology has been established to optimize the system for the operation in various line-of-sight conditions by adopting the maximum-ratio-transmission (MRT) and zero-forcing (ZF) MIMO algorithms. A two-user MIMO case study has been considered for the evaluation of the key system performance metrics, i.e., the effective isotropic radiated power, power consumption, signal-to-noise-ratio (SNR), and signal-to-interference-plus-noise-ratio (SINR). This study demonstrates that the phased-array fed reflector concept has a major advantage over traditional direct-radiating phased-array (DRPA) antennas to reduce energy consumption. In the present example, it requires 12–14 dB less transmitted power as compared with the MRT-beamformed DRPAs for the same SNR, and 26–27 dB less transmitted power relatively to ZF-beamformed DRPA systems for the same SINR. A prototype, employing a 55 cm diameter torus reflector and operating at 28 GHz-band, has been manufactured and tested. The measurement results agree well with simulations.