In this paper, we quantified the permittivity and permeability of ferrite-particle-containing silicone using a perturbation method with a harmonic resonator and investigated whether the modified silicone can be used as a material for fabricating heating vessels for microwave ovens. The material constant varied depending on the compounding ratio of the obtained ferrite. From our simulation results using a microwave oven model, we confirmed that the container was well heated and that the food in the container was heated by the remaining energy.
The algorithmic efficiency offered by sphere decoding when compared with enumeration technique makes it a better choice for direct model predictive control of power converters. However, the application of sphere decoding algorithm requires that the converter’s model should have the same state transition and input matrices irrespective of switch position and continuous/discontinuous conduction mode. Whereas, in power electronics we usually encounter such models, e.g. the model of the dc-dc boost converter. In this paper, we propose a branch and bound control algorithm inspired from sphere decoding for the current control of boost converter. The simulation results, verified by experimental results show that the proposed control algorithm produces same results as enumeration algorithm while being computationally efficient.
This work ideates a novel approach for designing a QR-incorporated data encoding structure that functions as a fully-passive, chipless radio frequency identification (RFID) tag. Several concentric square-shaped resonant slots embedded strategically within a QR-patterned region constitute the tag. A functional prototype is realized over an ungrounded Duroid® 5880 substrate, and the same is evaluated for its electromagnetic performance. The tag performs encoding of up to 118 data bits distributed across spectral and optical domain in a compact form factor measuring 55 × 55 mm2. Possible applications of the formulated tag include multi-layer authentication for secure access control in smart cities and connected homes.
This study proposes the investigation of using the (NH4)2Sx solution to form the AlGaN surface passivation on the AlGaN/GaN high electron mobility transistors (HEMTs). Both treatment schemes are implemented on separate pieces of the same HEMT wafer, including (NH4)2Sx pre-gate and post-gate metal treatments. Temperature-dependent characteristics of the HEMTs are also studied. Experimental results demonstrate that by the surface treatment prior to metal, the performance of the studied HEMTs can be improved, including thermal stability, dc and high-frequency characteristics. Furthermore, the interface state density (Dit) of the studied HEMT is studied by the subthreshold slope method. To the best of our knowledge, this is the first report on comparison of AlGaN/AlN/GaN HEMTs with pre-gate and post-gate metal treatments.
A new SiC trench MOSFET (T-MOSFET) integrated with a side-wall Schottky Barrier Diode (SBD) to form a compact power device is proposed. The proposed structure applies two trenches to form the n-channel and SBD in a single cell, respectively. A P+ is implanted after etching the trenches to form a shield for both the gate oxide and the Schottky barrier. The breakdown voltage of the proposed one is about 363% larger than that of the conventional trench MOSFET (CT-MOSFET) with integrated SBD. The integrated SBD of the proposed T-MOSFET exhibits an ultra-low leakage current (1 µA/cm2) and low forward voltage drop (Von_diode ≈ 0.9 V), as well as low reverse recovery charge (Qrr = 0.73 µC/cm2).
This paper proposes to utilize a structure of thin BOX FDSOI in analog circuit design. The thin BOX layer is utilized to create area efficient capacitors. The design experiment shows that the combination of the thin BOX layer capacitor and a metal fringe capacitor improves the capacitance by 92% in comparison with the metal fringe capacitor only. Another advantage of the thin BOX FDSOI technology is the high controllability of the threshold voltages of transistors. As a demonstration of utilizing the advantage in analog circuit design, we designed a PMOS-type Dickson charge pump with dynamic threshold voltage control. The designed charge pump achieves 5.7 times larger output current and 3.5 times higher energy efficiency than a conventional charge pump.
This paper presents a fractional-N frequency synthesizer for ultra high frequency radio frequency identification (UHF RFID) reader application. With the use of a novel parallel dual inductance resonator in the inductance and capacitance based voltage-controlled oscillator (LC_VCO), the resonator cavity loss was greatly reduced as well as the temperature drift was suppressed. At the same time, the loop linearity is improved by the use of operational amplifier tracking technology. The chip is fabricated in a 0.13 µm RF CMOS technology with a single 1.2 V power supply. The synthesizer provides a tuning range from 840 MHz to 960 MHz. The worst phase noise of −95 dBc/Hz in band, −110 dBc/Hz@100 kHz offset, −135 dBc/Hz@1 MHz offset with a reference spur of −78 dBc are measured at a center frequency of 920.125 MHz. A 0.95 ps integrated RMS jitter and an 18.5 mW power dissipation are obtained at a temperature range from −40°C to 85°C.
This paper proposes a method that renders the weights of the neural network with quaternary synapses map into the only four-level memristance of memristive devices. We show this method is capable of operating with a negligible loss in classification accuracy when the memristors utilized can store at least four unique values. Compared with other state-of-the-art methods, the method presented can achieve 98.65% accuracy under the 0.60M parameters. Systematic error analysis shows that the network can still reach over 95% accuracy under the condition of 95% yield of memristor crossbar array, 100 µV op-amp offset voltage and 0.5% Single-Pole-Double-Throw switches noise.