Applied Mechanics and Materials Vols. 519-520

Abstract: Performance boosting of modern computing systems is constrained by the chip/circuit power dissipation. Dynamic voltage scaling (DVS) has been applied for reducing the energy consumption by dynamically changing the supply voltage. One can apply an adaptive scheme by computing a threshold speed of the supplied voltage, and adopting greedy online DVS scheduling algorithm when the voltage exceeds the threshold while choosing a conservative speed on the contrary. This paper presents an algorithm to determine the threshold speed. The proposed algorithm allows to obtaining the threshold speed for the adaptive DVS scheduling algorithm more efficiently.

Abstract: Based on the currently most wide-used ARM and ZIGBEE-based intelligent application control system, a infrared self-learned remote controller was designed. This paper introduces the software structure and hardware structure of Infrared self-learned remote controller design scheme and extraordinarily expands the main interface design of Infrared self-learned remote controller and the long-distance control approach based on WEBKIT technology. According to the test result, the Infrared self-learned remote controller designed in this paper is capable to achieve both network remote and centralized control of applications equipped with remote controllers.

Abstract: Lithium battery is widely used in recent years. In this paper, an improved battery model combined with the equivalent circuit model and the electrochemical model is established. The main efforts of our study are: Firstly, the Ohmic resistance of the battery model is identified online based on the Unscented Kalman Filtering (UKF) algorithm. Secondly, the estimation model of the State of Health (SOH) for the 18650-type battery is established. Thirdly, an improved battery SOH estimation method based on UKF algorithm is proposed. The experimental results indicate that our new battery model considers the different value of the battery internal resistance on the different working condition, like the different voltage, the different current and the different temperature.

Abstract: Sigma-Delta (∑∆) modulators are commonly used in high-resolution analog-to-digital converters (ADCs). In this paper, a high-performance modulator targeted for ultra-high-frequency (UHF) radio-frequency identification (RFID) zero-intermediate frequency (ZIF) receivers is designed in standard 0.18μm CMOS technology. The modulator has been designed with switched-capacitor (SC) integrators employing gain-boosted operational amplifiers, voltage comparators and nonoverlapping clock generators to satisfy such requirements as high gain, low voltage and wide bandwidth. The behavioral-level modeling and circuit-level design are carried out with MATLAB/Simulink and Cadence/SpectreRF, respectively. Ultimately, the high-speed and low-power realization of a second-order single-bit modulator with an oversampling ratio (OSR) of 32 is presented. Simulation results shown that, from a 1.8V supply, operated at a sampling frequency of 64MHz, a dynamic range of 53.4dB over a signal bandwidth of 1MHz is achieved.

Abstract: Hetero-junction Bipolar Transistors (HBTs) have become very promising devices for power amplifier design in different communication applications. This paper proposes an analytical large signal model to predict nonlinear behavior of InGaP/GaAs HBT. The proposed model is directly fitted from linear model elements using Fourier transfer functions. As a consequence, the proposed large signal model shows good insight of circuit nonlinear behavior, and can be used to analysis large signal parameters of power amplifier. Based on the proposed large signal model, power gain and phase variation of an emitter follower amplify stage under different bias conditions have been analyzed. The calculated results show that: both gain and phase properties exhibit reverse deviation in saturation compared with that in forward amplify region, and can be used to maximize the linearity of power amplifier.

Abstract: A novel low phase noise LC Voltage Controlled Oscillator (LC-VCO) is designed in standard 0.18μm CMOS technology. Instead of common NMOS cross-pairs for a conventional complementary LC VCO, both body-biasing and Q-enhancement techniques are employed to provide a larger negative resistance for the VCO. Post-layout simulations showed that it can oscillate at a frequency range of 4.34-4.73GHz, and comsume a supply current of 1.52mA from a supply voltage of 1.8V. The VCO achieves a phase noise of -132.8dBc/Hz @ 1MHz offset and a figure of merit (FOM) of -195.9dBc/Hz at the frequency of 4.5GHz. A die area of 475μm×498.6μm is occupied.

Abstract: In order to meet the requirements of the operation, maintenance of intelligent substation, asked the test software and test equipment based on network communication platform, should according to the requirements of intelligent station to provide the corresponding test plan and test method, similar to a traditional stand test. In order to realize the computer PC and controller of wireless communication, which makes the system controller position and the testing is convenient and flexible, this paper puts forward the overall design scheme of a WIFI function modules to incorporate WIFI to intelligent substation distributed test system, the results show that the scheme is feasible.

Abstract: Design method for a class of novel high voltage high frequency electric source was investigated. This electric source could serve as discharging device for both corona generator and ozone generator. Through self-turning of power angle, the electric source could adjust itself within a certain frequency according to variations of the loads. In this way, the electric source could stay within the state of resonance oscillation so as to maximize discharging efficiency. Using TMS18LF2407A (DSP component produced by TI corporation) as the core device, the electric source guaranteed high working frequency and strong control functions.

Abstract: The DC-DC module is designed for the 300W Photovoltaic (PV) inverter with a former push-pull DC-DC boost. A UC3846 is applied to generate PWM signal. As the double-loop feedback, the output current and voltage are utilized in the circuit with the PID adjustment to improve the response speed. Finally, the simulation and experiment results are presented to illustrate the effectiveness of the proposed DC-DC converter.

Abstract: The thermoacoustic electricity generator system can convert heat from the low quality heat source such as automobile exhaustsolar energyindustrial waste heat etc into electricity. But battery Harvests a little charging power from the system due to the soft load characteristic, which restricts the application of the thermoacoustic electricity technology. In order to improve the Harvesting ability of battery charging power , a mathematical model of the thermoacoustic electricity generator battery system are established and a charging power harvesting control strategy is put forward in this paper. The modelingsimulation and control of charging power maximization harvesting are systematically investigated by computer-aided analysis in Matlab.