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A broadband high-data-rate ${D}$ -band OOK transmitter (TX) is designed in this article for high-speed communication. The TX consists of an adjustable signal source, a broadband high-speed OOK modulator, and a wideband low-noise power amplifier (LNPA). The proposed LNPA can be utilized simultaneously in both the TX and the receiver to improve the RF bandwidth of the system, thus increasing the data transmission rate. Additionally, a dual-mode balun was utilized, which is compatible with single-ended and differential interfaces. The TX was fabricated in a 28-nm bulk CMOS process and achieved more than 5-dBm output power under 1-V supply voltage with 167-mW dc power consumption. For testing purposes, the TX is connected to a receiver via wire bonding, achieving a data rate of 32 Gbps in the OOK modulation scheme. Moreover, a wideband antenna was designed and implemented on printed circuit board (PCB) for the over-the-air (OTA) transmission, supporting data rates of 20 Gbps at a distance of 6 cm. To the best of our knowledge, this work demonstrates the widest RF bandwidth and the highest data rate in TXs without predistortion and equalization, which can provide excellent performance for ${D}$ -band high-speed communication.

This article presents a prototype of a two-way differential power-combining sub-terahertz (sub-THz) power amplifier (PA) utilizing a coupled-line-balun network in a 0.13- $\mu \text{m}$ SiGe BiCMOS process with $f_{t}/f_{\text {max}}$ = 350/450 GHz. To achieve optimum load impedance matching and power combining simultaneously in a sub-THz band, a modified design method based on the characteristic impedance and electrical length of a coupled line is proposed. This method employs offset coupled lines and additional compensated transmission lines (T-lines) to obtain a wide single-ended-to-differential impedance transformation range. Furthermore, the influence of bypassed capacitances on common-mode performance is also analyzed, and the metal–oxide–metal (MOM) capacitor is used in the balun design. The proposed power combiner and splitter occupy a compact area of less than $125\times 90\,\,\mu \text {m}^{2}$ . The sub-THz four-stage PA utilizing the proposed techniques exhibits a peak gain of 21.4 dB at 259 GHz, a 3-dB small-signal bandwidth of 33 GHz (242–275 GHz), and a 3-dB saturated power bandwidth of 41 GHz (241–282 GHz). A measured maximum saturated power of 12.5 dBm and the corresponding power-added efficiency (PAE) of 2.26% at 265 GHz verifies the effectiveness of the proposed modified design method.

The temperature of a friction pair exerts considerable influence on the tribological behavior of a system. In two cases, one with and the other without Cu (copper) nanoparticles, the temperature increase in friction pairs caused by frictional heating and its tribological properties at various temperatures are studied by using the molecular dynamics approach. The results show that temperature distribution and surface abrasion are significantly improved by the presence of Cu nanoparticles. This is one of the reasons for the improvements in tribological properties achieved in the presence of nanoparticles. The temperature and range of influence of frictional heating for the model without nanoparticles are significantly increased with the increase in the sliding velocity; however, in the model with nanoparticles, the temperature gradient is confined to the area near the Cu film. With an increase in the temperature of the friction pair, the improvement in anti-wear properties associated with the presence of Cu nanoparticles becomes more significant.

Biomass-derived photothermal conversion materials are considered to be promising evaporator choices for cost-effective, sustainable, and environmentally friendly solar vapor generation. Herein we demonstrate a double-layer flamed straw, which is a typical solar-driven interfacial evaporator that can directly convert solar energy into heat and then localize heat at interface for vapor generation. Benefiting from the unique structure of a natural corn straw, the flamed straw exhibits a high solar absorbance of 91%, ultralow thermal conductivity (0.042 W m–1K–1), and a sufficient water supply. Notably, the flamed-straw evaporator achieves a fast evaporation rate of 1.497 kg m–2h–1and a high photothermal efficiency of 86% under 1 sun illumination, showing comparable efficiency with the reported studies. Our work highlights the promise of using the low-cost biomass-derived materials as highly effective solar vapor generators in the realm of seawater desalination and wastewater treatment.

Due to their good approximation accuracy and local fitting characteristics, the moving least squares (MLS) and moving total least squares (MTLS) methods are widely used in various engineering fields. However, neither of these two methods is robust and they cannot effectively deal with outliers in measurement data. To eliminate the negative influence of outliers and achieve robust reconstruction, a novel MTLS method is proposed in this paper, which introduces local Bayesian estimation combined with clustering using representatives (CURE) algorithm. In the support domain, this method adopts a two-step process to remove the abnormal points and adjust the weights of discrete points through compound weighting. Bayesian estimation is first performed on discrete points to derive the reference model, and the residuals are calculated as the input of CURE clustering. The points with large residuals are classified into one cluster and removed. The remaining points undergo repeated processing until the iteration concludes. A gradient weight function based on the residuals and a compact support weight function are combined to determine the final estimated value using weighted Bayesian estimation. The simulations and experiments demonstrate that the proposed reconstruction method achieves excellent accuracy and robustness, surpassing several existing methods when handling highly contaminated datasets. [ABSTRACT FROM AUTHOR]