Applied Mechanics and Materials Vol. 441

Abstract: A 5.8GHz single-stage low noise amplifier (LNA) for radio frequency identification devices (RFID) applications was proposed according to the theory of LNA. It has been realized by ATF-541M4 transistor and its peripheral circuit, such as bias circuit, input and output matching network. The proposed LNA provides a gain of 12.696dB from the analysis of ADS. The LNA achieves 0.951dB noise figure (NF) at the frequency of 5.8GHz. The simulation results show that this LNA has good noise characteristic, the NF is less than other published paper.

Abstract: In this Paper, a 8-way Microwave Equal Power Divider with Substrate Integrated Waveguide Technology is Proposed and Designed . the Substrate Integrated Waveguide Power Divider with Metal pin Inductance is Investigated and Simulated. the Center Frequency is 9.5GHz, and the Operating Frequency Band is more than 1GHz. the Maximal Insert Loss is Less than 1dB from 9GHz to 10GHz. the Impedance of each Ports is 50Ω.

Abstract: Arbitrary integer frequency divider based on single chip microcomputer proposed an arbitrary integer frequency divider design scheme within 100 for digital clock signals. Microcontroller detected the parity of the points frequency which was inputted by the external keyboard, and then controlled the switching controller switched the point frequency circuit between odd points frequency circuit and even. Therefore, a circuit design could solve problem along with the changing of the circuit and the heavy labor for changing the frequency num that existed in traditional divider .So it greatly reduced the cost.

Abstract: Partial discharge is one of the most common fault of power cable. It is of great significance to detect and analyze the condition of the power cable and locate the fault of the power cable. The model of partial discharge signal is constructed by a double exponential function. The simulation model of power cable with a middle fault is built by MATLAB SIMULINK. The transmission characteristic of partial discharge in different length of power cable and different types of power cable is simulated respectively. The simulation results show that the attenuation is proportional to the length of the same type of cable and the primary parameter of different type of power cables determines the attenuation.

Abstract: In the long run, the problem of high temperature has been existed in a companys injection molding machine controller. In order to solve the heat dissipation problem, two kinds of heat pipe heat dissipation schemes are designed, CFD software ICEPAK is used in the report to make a numerical simulation as well as a simulation analysis of the Heat pipe cooling scheme. By comparing two kinds of cooling mode heat pipe cooling effect and structure process, Vertical-type heat pipe cooling solution that meets the cooling requirements and makes heat-sensitive components stay away from high-temperature, furthermore heat pipe processing technology is relatively simple.

Abstract: A miniaturized multi-frequency antenna is proposed. The proposed antenna can generate three separate impedance bandwidths to cover all the 2.4/5.8 GHz WLAN/RFID operating bands and the 2.5/3.5/5.5 GHz WiMAX bands. The proposed microstrip-fed antenna mainly consists of a circular ring, four semicircular rings, a rectangle strip, and a defected ground plane. By adding four semicircular rings in the circular ring, the antenna excites two resonant modes and is with miniaturization structure. Because of the introduction of the cambered ground plane with an circular-defect, the third wide band with better impedance matching is obtained. A prototype is experimentally tested, and the measured results show good radiation patterns and enough gains across the operation bands.

Abstract: A kind of wideband plasma monopole antenna is proposed, such as circular plasma monopole antenna based on circular monopole theory. The impedance and radiation characteristics of this antenna are simulated. The results show that the band width with return loss below-10dB of the circular plasma monopole antenna can get 123%.

Abstract: TEM horn antenna is one kind of directional Ultra-wideband antenna with simple structure. Based on the design method of TEM horn antenna, satisfied impedance and radiation character are obtained by simulation and experiment research. On this basis, by means of metal ridged loaded, background dielectric material loaded and distributed lossy metal loaded respectively, the miniaturization character is realized. The simulation analysis results show that load of traditional TEM horn antenna can get efficiently improvement in structure and performance which have widely application foreground in pulse radiation communication system and ultra-wideband radar system.

Abstract: Voltage sag assessment of distribution network with DGs based on Monte Carlo method is researched in this paper. Models of synchronous machine type DG and inverter type DG are established respectively; then a typical distribution network with DGs is simulated based on PSCAD/EMTDC. Impacts of type, control strategy, output power and location of DG on voltage sags are discussed based on several simulation examples. The results show that inverter type DG has certain capability of suppressing voltage sags and can reduce the frequency of voltage sags in distribution network and the impacts are depend on its type, control strategy, output power and location.

Abstract: Solid State Transformer (SST) has many attractive characteristics, including power quality improvement and reactive power compensation. The paper investigates the topology and control schemes of SST, and discusses its flexibility and reliability for both grid and customers. A model of SST applied for distribution network is constructed, and simulation shows the SST with appropriate control scheme can provide excellent power supply during both steady-state and dynamic-state with varying load.