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Large-scale millimeter-wave (mm-Wave) integrated phased array is the key technology to enable broadband 5G and satellite communications. This paper details the design considerations, challenges and trade-offs of mm-Wave integrated phased arrays based on bulk CMOS and multi-layer hybrid PCB technologies. Both technologies attain high yield and low cost for mass production. Important beamforming building blocks are addressed and compared in detail. Demonstrators of integrated phased arrays are presented from circuit to board levels. The 1024- and 4096-element integrated phased arrays achieve the EIRP of 72.5 and 84.0 dBm respectively. Finally, relevant phased-array transceivers and antennas from the recent literature are discussed. [ABSTRACT FROM AUTHOR]

This article presents a Ku-band power amplifier with a series-shunt LC notch filter in 65-nm CMOS. The notch filter is integrated into the inter-stage matching network to attenuate the receiver-band noise, thereby reducing transmitter-to-receiver interference. A comprehensive analysis of the series and the shunt notch filters, as well as the position to apply the notch filter is discussed. Besides, a systematic method of optimizing passive devices in the notch filter is proposed to further improve network Q and minimize the influence on the power amplifier. Fabricated in 65-nm CMOS technology, the power amplifier prototype delivers a measured gain of 21.9 dB with 3-dB bandwidth from 13.7 GHz to 16.7 GHz at the nominal state. At 14.2 GHz, it can offer a saturated output power of 14.5 dBm with peak power added efficiency of 24.1%. The notch frequency is adjustable from 10.3 to 11.9 GHz to offer the best attenuation at the receiver band. From 10 to 12 GHz, a maximal attenuation of 30 dB is achieved. The design occupies a core area of 0.35 × 0.85 mm2. [ABSTRACT FROM AUTHOR]

The reliability of key components of urban rail transit (URT) plays an important role in the maintenance plans of URT. It is necessary to establish the reliability model of URT trains. In the current research, the reliability model has a limited scope of application and fails to accurately depict the reliability of key components in URT trains. To solve the above problem, a multi-peak type mixture Weibull distribution model is established using several three-parameter Weibull distributions based on fault modes of components sourced from historical lifetime data. Due to the complexity of this model, parameter estimation is challenging. For this purpose, an improved hunter-prey optimization (IHPO) was proposed to improve parameter estimation accuracy. Firstly, an improved Hénon chaos map was introduced to improve the distribution of the initial population. Secondly, the Lévy flight was introduced to increase the probability of the individual spreading to the whole range at the late stage. Lastly, a nonlinear balance factor was proposed to enhance the algorithm’s global search capability. The simulation experiment was carried out with examples of the balanced pressing wheel and the wheelset. The IHPO algorithm-based parameter estimation method shows the highest R-square with values of 0.996 and 0.999, respectively, and the lowest root mean square error with values of 0.019 and 0.008, respectively. The simulation results demonstrate that the stability and optimization of the HPO are improved, and the multi-peak mixture Weibull distribution model based on the IHPO can accurately depict URT trains’ reliability.

In the above article , Table III makes the comparison between the phase shifters with different topologies. The work in is referred in the comparison table, which presents the designs of two active vector-modulated phase shifters (VMPS). In , one of the presented test chips is with relatively small chip size and the other shows increased gain. In Table III of the work in , only the design with small chip size is included. For the completeness of the comparison, the performances of both designs are now shown in. [ABSTRACT FROM AUTHOR]