The design and analysis of a dual-operating mode laterally diffused metal-oxide semiconductor (LDMOS) power amplifier for code-division multiple-access wireless communication base-station applications is presented in this paper. The amplifier structure consists of four parallelly located single-stage LDMOS amplifier array, the dual-mode input power divider, and output power combiner. In this dual-mode operation, the number of operating power amplifier (either one or four amplifiers) is controlled depending on the required power level. This results in significant improvement in efficiency performance of the amplifier by minimizing unnecessary dc power consumption. In addition to the enhancement of efficiency, the amplifier design approach also provides better overall linearity performance. The proposed dual-operating mode design technique was successfully demonstrated by designing, implementing, and testing an LDMOS power amplifier with Motorola MRF 21030 in this study

In this letter, a continuous conduction mode boost converter with fast and efficient maximum power point tracking (MPPT) is presented for energy harvesting application. A novel current conservation technique is utilized to sample open-circuit voltage of energy harvesting device without any unnecessary power loss during MPPT operation. Fabricated in 0.35 μm CMOS process, the proposed converter achieves a sampling and tracking time of 80 ns for MPPT. Also, the converter has a peak tracking efficiency of 97.2% and a peak power conversion efficiency of 84.8% with 3-V output voltage.

Advanced algorithms of image quality enhancement have been attracting substantial attention recently due to the successful business model of video streaming services. The extremely high image quality in video streaming demands a significant increase in the transmit data rate. In turn, the required ultrahigh data rate causes the saturation of the video streaming service network if there is no remedy for this situation. Compression algorithms have contributed to the energy-efficient transmission of data; however, they have almost reached the upper bound. The demand for ultrahigh image quality by the user is significantly increasing. Meanwhile, minimizing data transmission is inevitable in energy-efficient communications. Therefore, to improve energy efficiency, we propose to decrease the image resolution at the transmitter (Tx) and upscale the image at the receiver (Rx). However, standard upscaling does not yield ultrahigh-quality images. Deep machine learning contributes to image super-resolution techniques with the cost of enormous time and resources at the user end. Hence, it is inappropriate for real-time applications. With this motivation, this paper proposes a deep machine learning-based real-time image super-resolution with a residual neural network on the prevalent resources at the user end. The proposed scheme provides better quality than conventional image upscaling such as interpolation. The comprehensive simulation verifies that our scheme substantially outperforms the conventional methods, utilizing the seven-layer residual neural network.

In this work, we investigate the magnetization switching behavior of IrMn/NiFe bilayers as a function of NiFe thickness, temperature, and cooling-field direction. An unusual double-loop hysteresis behavior is observed in IrMn 10 nm/NiFe 40 nm bilayers, whereas a conventional single-loop hysteresis behavior is obtained for thinner NiFe layers. The observed double-loop feature exhibits temperature- and cooling-field-dependent asymmetry, suggesting a spatially nonuniform exchange interaction at the IrMn/NiFe interface. The opposite evolution of switching fields under positive and negative cooling fields indicates competing exchange contributions within the bilayer system. These results are consistent with a model involving distinct interfacial exchange regions or nonuniform uncompensated spin configurations in the IrMn layer. Our findings provide insight into the complex interfacial exchange behavior responsible for double-loop hysteresis in IrMn/NiFe bilayers and highlight the importance of interfacial magnetic inhomogeneity in exchange-biased spintronic structures.