The design of a novel practical 28 GHz beam steering phased array antenna for future fifth generation (5G) mobile device applications is presented in this paper. The proposed array antenna has 16 cavity-backed slot antenna elements that are implemented via the metallic back casing of the mobile device, in which two 8-element phased arrays are built on the left- and right-side edges of the mobile device. Each 8–element phased array can yield beam steering at broadside and gain of >15 dBi can be achieved at boresight. The measured 10-dB return loss bandwidth of the proposed cavity-backed slot antenna element was approximately 27.5 GHz to over 30 GHz. In addition, the impacts of user’s hand effects are also investigated.

In this paper, we have introduced a compact eight-element antenna array for triple-band MIMO (multi-input multi-output) operation in 5G (fifth generation) mobile terminals, which consists of two symmetric four-element sub-arrays disposed, respectively, along two long side-edges of the system ground plane of the mobile terminal. This antenna element can operate at two dual-wideband of 3250-3820 MHz and 4790-6200 MHz with three resonance frequencies which can fully cover 5G NR (New Radio) Band-N78 (3300-3800 MHz), China 5G-Band of 4800-5000 MHz and LTE Band-46 (5150-5925 MHz). The main parameters that characterize the performance of the proposed MIMO antenna system, such as bandwidth, reflection coefficient, isolation (more than 10.5 dB), total radiation efficiency (more than 43%), ECC (envelope correlation coefficient, less than 0.12) and CC (channel capacity, 34.9-37.6 bps/Hz), are analyzed and presented in this paper. Besides, the effects of single-hand and dual-hand on performance of the MIMO antenna system are also discussed. The structure of antenna element is only 15 mm×3 mm (0.175 λ0 × 0.035 λ0，λ0 is the free-space wavelength at the frequency of 3.5 GHz) with a very small ground clearance of 13 mm×2 mm on the main board of the proposed mobile terminal. The antenna system has the possibility to be used in 5G mobile terminals with triple-band operation, narrow frame and large display. The corresponding antennas prototype is fabricated and measured; and a quite good agreement between simulation and measurement is obtained.

A novel fan-out wafer-level packaging (FOWLP) technology with double-sided redistribution layers (RDLs) and tall copper vertical interconnects is described. The design of a dual-polarized magnetoelectric (ME) dipole antenna based on this new packaging technology is presented. It is shown that the antenna with a size of $10\times10$ mm ² achieves good impedance matching and a stable radiation pattern over a wide bandwidth from 25 to 43 GHz, which can cover most of the millimeter-wave (mmWave) bands of the fifth-generation (5G) mobile networks in different countries. The measurement results demonstrate that the antenna is well suited for FOWLP technology and can be used for phased-array modules in 5G wireless communication systems.

In this paper, a K-band antenna with ±60° beam scanning is proposed for a mmWave (millimeter-Wave) radar sensor. Especially, we take advantages of the magnetic dipole principle, and design the antenna by employing via holes in three sides, so as to form a cavity which can be equivalently considered as magnetic dipole, resulting in the 3 dB beam width as wide as 140° in E-plane. We cascade the mmWave antenna to 4×1 and 4×4 arrays for radar transmitting and receiving, respectively. The antenna array is fabricated and implemented to a K-band radar and its wide-angle beam scanning performance is evaluated by the radar’s distance and angular detections.