A 28 GHz 2 × 2 Antenna Array with 10 Beams Using Passive SPDT Switch Beamforming Network

In this paper, a dual-polarized four-port 2 × 2 series fed antenna array operating at 28 GHz with beam-switching capability is proposed. The antenna array uses a simple passive beamforming network to switch the main beam. The presented antenna design is suitable for 5G user equipment and high data rates applications by which it has a compact size with low cost and complexity. The size of the antenna is 37.2 × 37.2 mm2 including the ground plane, and it produces 10 different switched beams by using only two simple 3 dB/90∘ couplers which create the required amplitudes and phase excitations for the antenna elements. A one-port simple feeding mechanism including Peregrine PE42525 SPDT switch modules and a power divider is used to generate and measure the 10 switched beams. The antenna design is implemented on a two-layer 0.203 mm thick low-loss (tanδ = 0.0027) Rogers 4003C substrate, and it has a measured 10 dB impedance bandwidth of 4 GHz (14.3%, from 26 GHz to 30 GHz) for all ports. Measured peak isolation between any dual-polarized ports of the antenna is better than 30 dB. The antenna has an average measured realized gain of 8.9 dBi and around 10 dB side lobe level (SLL) for all beams. The antenna has 3-dB coverage of 80∘ to 90∘ in 2D space and it has a maximum of ±26∘ beam-steering angle. The antenna is designed and simulated using Ansys HFSS and fabricated using regular PCB processing.

SWITCHING SCANNING ANTENNA SYSTEM BASED ON A FLAT LUNEBERG LENS WITH CONCENTRIC RINGS

Антенные системы с возможностью широкоугольного сканирования довольно часто используются в современных системах беспроводной связи и радиолокационных системах гражданского и военного назначения. Особое внимание привлекли Smart-антенны (антенны с коммутируемым лучом и адаптивные антенные системы), а также фазированные антенные решетки (ФАР). В работе рассмотрен вариант построения ФАР с коммутационным сканированием с диаграммообразующей схемой в виде плоской линзы Люнеберга, состоящей из системы концентрических диэлектрических колец, размещенных на подложке из материала Rogers 5880. Исследованы влияние кронштейна крепления для ФАР на диаграмму направленности, уровень излучения, снижение коэффициента направленного действия и уровня сектора сканирования в азимутальной плоскости. Максимальный диаметр ФАР 160 мм, полная высота такой антенны получилась 38 мм. Запитка осуществляется при помощи коаксиальных кабелей с волновым сопротивлением 50 Ом. Диаметр самой линзы Люнеберга был выбран 80 мм; полная высота линзы мм. Подложка имеет толщину мм, склеенная слоем клея толщиной 0.025 мм. Концентрические кольца на этой подложке имеют высоту 0.787 мм. Минимальная ширина концентрического кольца (внешнего) мм (при резке УФ лазером минимальная ширина перегородки между отверстиями равна 0.05 мм). Полосковые трансформаторы расположены на плате из материала Rogers 5880 и имеют толщину равную мм Scanning antennas with wide-angle scanning capabilities are widely used in the areas such as modern wireless communications and military and civilian radars. Among them, lens antennas with switched beams and phased array antennas (PHAR) attracted considerable attention. In this paper, we consider a variant of the construction of switching scanning PHAR with a diagram-forming scheme in the form of a flat Luneberg lens consisting of a system of concentric dielectric rings placed on a substrate made of Rogers 5880 material. We studied the effect of the PHAR mounting bracket on the presence of its influence on the radiation pattern, the radiation level, the decrease in the directional coefficient, and the level of the scanning sector in the azimuth plane. The maximum diameter of the PHAR is 160 mm, the full height of this antenna is 38 mm. The power supply is carried out using coaxial cables with a wave resistance of 50 Ohms. The diameter of the Luneberg lens itself was chosen 80 mm; the full height of the lens is H =0.939 mm. The substrate has a thickness of t =0.127 mm, glued with a layer of glue, 0.025 mm thick. The concentric rings on this substrate are 0.787 mm high. Minimum width of the concentric ring (external) d - W =0.25 mm (when cutting with a UV laser, the minimum width of the partition between the holes is 0.05 mm). Strip transformers are located on the board made of Rogers 5880 material and have a thickness of H =0.939 mm

Assessment of Anchors Constellation Features in RSSI-Based Indoor Positioning Systems for Smart Environments

In this paper, we assess the features of a rectangular constellation of four anchors on the position estimation accuracy of a mobile tag, operating under the IEEE 802.15.4 specifications. Each anchor implements a smart antenna with eight switched beams, which is capable to collect Received Signal Strength Indicator (RSSI) data, exploited to estimate the mobile tag position within a room. We also aim at suggesting a deployment criterion, providing the discussion of the best trade-off between system complexity and positioning accuracy. The assessment validation was conducted experimentally by implementing anchor constellations with different mesh sizes in the same room. Mean accuracies spanning from 0.32 m to 0.7 m on a whole 7.5 m × 6 m room were found by varying the mesh area from 1.19 m2 to 17 m2, respectively.