Efficient Ultra High Voltage Controller Based Complementary Metal Oxide Semiconductor Switched Capacitor DC-DC Converter For Radio Frequency Micro Electro Mechanical Systems Switch Actuation

Achieving wireless connectivity in ever smaller, lower power portable devices with increasing number of features and better radio-frequency (RF) performance is becoming difficult to fulfill through existing RF front-end technology. RF micro-electro-mechanical systems (MEMS) switch technology, which has significantly better RF characteristics than conventional technology and has near-zero power consumption, is one of the emerging solutions for next generation RF front-ends. However, to achieve satisfactory RF MEMS device performance, it is often necessary to have an actuating circuitry to generate high direct current (DC) voltages for device actuation with low power consumption. In this study, the authors present an RF MEMS switch controller based on a switched-capacitor (SC) DC-DC converter in a 0.35 μm CMOS technology. In this design, novel design techniques for a higher output voltage and lower power consumption in a smaller die area are proposed. The authors demonstrate the design of the high-voltage (HV) SC DC-DC converter by using low-voltage transistors and address reliability issues in the design. Through the proposed design techniques, the SC DC-DC converter achieves more than 25% higher boosted voltage compared to converters that use HV transistors. The proposed design provides 40% power reduction through the charge recycling circuit. Moreover, the SC DC-DC converter achieves 45% smaller than the area of the conventional converter

Interframe Bus Encoding Technique and Architecture for MPEG-4 AVC/H.264 Video Compression

In this paper, we propose an implementation of a data encoder to reduce the switched capacitance on a system bus. Our technique focuses on transferring raw video data for multiple reference frames between off-and on-chip memories in an MPEG-4 AVC/H.264 encoder. This technique is based on entropy coding to minimize bus transition. Existing techniques exploit the correlation between neighboring pixels. In our proposed technique, we exploit pixel correlation between two consecutive frames. Our method achieves a 58% power saving compared to an unencoded bus when transferring pixels on a 32-b off-chip bus with a 15-pF capacitance per wire

Speedy Derivative-Corrective Mass Spring Algorithm For Adaptive Impedance Matching Networks

Adaptive impedance matching algorithms are used to preserve the link quality of mobile phones, under fluctuating user conditions. It is highly desirable to reduce the search time for minimising the risk of data loss during the impedance tuning process. Presented is a novel technique to reduce the search time by more than an order of magnitude by exploiting the relationships among the mass spring's coefficient values derived from the matching network parameters, thereby significantly reducing the convergence time of the algorithm

Novel Dynamic Partial Reconfiguration Implementation of K-Means Clustering on FPGAs: Comparative Results with GPPs and GPUs

K-means clustering has been widely used in processing large datasets in many fields of studies. Advancement in many data collection techniques has been generating enormous amounts of data, leaving scientists with the challenging task of processing them. Using General Purpose Processors (GPPs) to process large datasets may take a long time; therefore many acceleration methods have been proposed in the literature to speed up the processing of such large datasets. In this work, a parameterized implementation of the K-means clustering algorithm in Field Programmable Gate Array (FPGA) is presented and compared with previous FPGA implementation as well as recent implementations on Graphics Processing Units (GPUs) and GPPs. The proposed FPGA has higher performance in terms of speedup over previous GPP and GPU implementations (two orders and one order of magnitude, resp.). In addition, the FPGA implementation is more energy efficient than GPP and GPU (615x and 31x, resp.). Furthermore, three novel implementations of the K-means clustering based on dynamic partial reconfiguration (DPR) are presented offering high degree of flexibility to dynamically reconfigure the FPGA. The DPR implementations achieved speedups in reconfiguration time between 4x to 15x

Low-temperature chemical looping oxidation of hydrogen for space heating

Chemical looping combustion (CLC) is an advanced combustion process in which the combustion reaction splits into two parts; in the first reaction metal oxides are used as oxygen suppliers for fuel combustion and then in the second reaction, reduced metal oxides are re-oxidised in an air reactor. Although this technology could be applicable for the safe implication of “low-temperature oxidation of hydrogen”, there is limited understanding of oxygen carrier reduction stages and the oxidation mechanism of hydrogen throughout the process. The novelty of this research lies in its pioneering investigation of low-temperature oxidation of hydrogen through chemical looping technology as a safe and alternative heating system, using three distinct metal oxide oxygen carriers: CuO, Co3O4, and Mn2O3. The oxidation of hydrogen over these oxygen carriers was comprehensively studied in a fixed-bed reactor operating at 200–450 °C. XRD analysis demonstrates that CuO directly reduced to metallic Cu at 200–450 °C, instead of following a sequential reduction step CuO→Cu4O3→Cu2O→Cu throughout the temperature. Co3O4 was reduced to a mixture CoO and Co at 450 °C, which may refer to a sequential reduction step Co3O4→CoO→Co with increasing the temperature. Decreasing the reduction temperature led to an elevation in CoO formation. Mn2O3 can also reduce to a mixture of Mn3O4 and MnO at temperatures between 250 and 400 °C. Compared to temperature, the increase in the residence time did not show any further reduction in Mn2O3. SEM results showed that most of the metal oxide particles were evenly dispersed on the supports. Based on the experimental results, a potential reduction stage of CuO, Co3O4 and Mn2O3 was proposed for low-temperature hydrogen oxidation, which could be a potential application for space heating using safe hydrogen combustion

New high-speed centre of mass method incorporating background subtraction for accurate determination of fluorescence lifetime

We demonstrate an implementation of a centre-of-mass method (CMM) incorporating background subtraction for use in multifocal fluorescence lifetime imaging microscopy to accurately determine fluorescence lifetime in live cell imaging using the Megaframe camera. The inclusion of background subtraction solves one of the major issues associated with centre-of-mass approaches, namely the sensitivity of the algorithm to background signal. The algorithm, which is predominantly implemented in hardware, provides real-time lifetime output and allows the user to effectively condense large amounts of photon data. Instead of requiring the transfer of thousands of photon arrival times, the lifetime is simply represented by one value which allows the system to collect data up to limit of pulse pile-up without any limitations on data transfer rates. In order to evaluate the performance of this new CMM algorithm with existing techniques (i.e. Rapid lifetime determination and Levenburg-Marquardt), we imaged live MCF-7 human breast carcinoma cells transiently transfected with FRET standards. We show that, it offers significant advantages in terms of lifetime accuracy and insensitivity to variability in dark count rate (DCR) between Megaframe camera pixels. Unlike other algorithms no prior knowledge of the expected lifetime is required to perform lifetime determination. The ability of this technique to provide real-time lifetime readout makes it extremely useful for a number of applications