An energy-efficient 5G phased array incorporating a novel vertically-polarized (V-pol) endfire planar folded slot antenna (PFSA) for user devices (UE) is presented. First, we analytically amend existing mmWave hybrid beamforming architectures that have precluded the uniqueness of 5G antennas and UEs. The total power consumption of the derived switchable 5G UE antenna system is estimated to be reduced by approximately 70% in comparison to a recently reported fully digital mmWave 5G UE antenna system under identical conditions. This is attributed to the ability to deactivate certain RF chains based on the directive nature of antenna elements. The PFSA featuring a height profile of less than 1/9 λ0 is derived from a planar folded slot structure. The designed and fabricated 1 × 4 PFSA array features impedance bandwidth of approximately 4 GHz with a center frequency of 37-39 GHz and the gain of 7.7 dBi with antenna efficiency of 94.12% at 39 GHz. A mmWave 5G beamforming module is demonstrated using the presented energy efficient 5G beamforming architecture and V-pol endfire PFSA array. The fabricated module achieves a measured EIRP of 18.2 dBm and scanning range of ±50° in azimuth at 28 GHz.

This paper proposes an antenna that employs the shared aperture concept, and is devised to simultaneously operate in the dual bands of Ku and Ka while supporting dual polarization. The antenna element is specified according to the four distinct derivation process. The port isolation is enhanced by using an indirect feeding mechanism through slot aperture coupling integrated with substrate integrated waveguide feed. Based on the antenna array theory, the extended array structure ensures optimized inter-antenna spacings. The reflection coefficient of the antenna element satisfies below -10 dB for both operating bands. Additionally, inter-port isolation surpasses 30 dB in Ku band and 20 dB in Ka band. For the demonstration of beam steering capabilities, distinct array structures are devised and constructed for each band. Both simulations and measurements for the Ku band feature a beam steering angle exceeding ±40 degrees for both polarizations, with a peak gain of 10.3 dBi based on a 1×3 array antenna structure. In the case of the Ka band, measurements and simulations consistently demonstrate a beam steering angle of no less than ±43 degrees across both polarizations. This results in a maximum gain of 13.1 dBi based on a 1×5 array antenna structure.

This letter presents an unprecedented stamped metal antenna-in-package (AiP) concept for millimeter-wave MIMO and phased array applications. The stamped metal antenna containing an aperture dually functions as an efficient heat sink. Moreover, the presented antenna topology can be mass-produced using stamping technology, which is widely used for conventional heatsinks. The ground wall of the proposed antenna encompassed by the dielectric substrate, which is thermodynamically equivalent to a cooling medium is connected to the shield structures to guide the convection heat emitted by the RFICs and discharge this heat into free space. Details of the proposed AiP topology are discussed and the parametric effects of the key design factors are quantitatively analyzed. To verify the proposed AiP, the optimized design is fabricated using standard PCB and press technology. The fabricated 1×8 subarray features an impedance bandwidth of 700 MHz with a center frequency of 28.5 GHz and a measured gain of 13.78 dBi. Computational fluid dynamics results ascertain that the proposed stamped metal AiP effectively discharge the heat emission generated from the RFICs.

This article describes a low-profile frequency-adjustable planar folded slot antenna (PFSA) system that is applicable to real-life smartphone platforms at the millimeter-wave (mmWave) 5G spectrum. Critical challenges that are attributed from the frequency discrepancy between sub-6 GHz and mmWave 5G are discussed. The multithrow topology is used to minimize the distortion of the far-field radiation pattern due to the beam squint while adjusting the resonant frequency between 27.95 and 28.65 GHz. The presented methodology entails using a multithrow switch chip directly on the transmission line, which enables a bistate function. The proposed methodology is exemplified into a 28 GHz 1 x 4 subarray. Measured and simulated results confirm that the frequency-adjustable PFSA features a 2.6-time enhanced impedance bandwidth and an average peak gain of 6.3 dBi while maintaining identical antenna volume in comparison to the previously reported PFSA.

The reduced link margins caused by undesired blockage such as the user's hand and inherent limitations of beamsteering angles for planar antenna components constitute one of the most critical challenges for future mmWave mobile devices. This underscores the need for a new beamforming antenna strategy, which can enhance the foreside coverage with minimum compromise. This article provides a detailed overview of an mmWave beamforming antenna concept denoted as an optically invisible antenna-on-display (AoD), which can enhance the CDF, especially in the foreside direction of mobile devices such as cellular handsets. In contrast to existing antenna component strategies, the AoD is integrated within the view area of high-resolution OLED or LCD display panels of cellular handsets while remaining unnoticeable to the human eye through the use of nano-scale patterns. This allows the realization of highly precise beamforming in the foreside direction for large-screen mobile devices. The fundamental phased-array AoD strategy is introduced and compared with existing mmWave 5G beamforming antenna strategies for mmWave 5G NR cellular handsets. The operating mechanism of the mmWave 5G phased-array AoD component and its integration with existing wireless component architectures and a 537 ppi density OLED panel are considered. This concept is further refined by integrating a series of fabricated 28 GHz phased-array AoD components within a real-life mmWave 5G NR Android-based cellular handset prototype reported in the literature for the first time. The foreside beamforming characteristics at 28 GHz are experimentally studied followed by investigation of OTA measured EVMs using QPSK, 16- and 64-QAM mmWave 5G NR waveform signals in accordance with the 3GPP requirement.