Applied Mechanics and Materials Vols. 321-324

Abstract: The paper gives a systemic classification to the common electric vehicle (EV). The technology of low power converter using as auxiliary power supply and high power converter using for traction system has been deeply discussed from the view of topology, control strategy and devices. Finally, the development tendency of on board DC conversion technology is prospected.

Abstract: In this paper, two fractal-based composite right/left-handed (CRLH) transmission lines (TLs) are proposed, and their applications in infinite wavelength resonant (IWR) antennas are investigated. In order to impose CRLH properties on the TLs, both the symmetric and asymmetric unit-cells include a gap for series capacitance and Peano-fractal curves for shunt inductance. The circuit parameters analysis shows that the proposed TLs can be used to design miniaturized IWR antennas with extended bandwidth. Then, two fractal-based IWR antennas are designed and fabricated. The measured results show that the fabricated antennas have advantages in terms of small size and wide bandwidth over the reported IWR antennas.

Abstract: RFID has been widely used in high security applications due to its contactless characteristic and security mechanism, such as e-ticket, e-money, e-key and so on. Since magnetic stripe card and traditional Mifare RFID card can be broken, it is a general trend to change them with CPU card. Based on the above fact, an entrance access control system is proposed in this paper using ISO/IEC 14443-A standard to replace some unsecure card. The following measures were introduced: 1, to design a kind of RFID reader which can be easily installed on the entrance; 2, to introduce PSAM card and its security function; 3, to design a security authentication mechanism using random number and 3DES encryption algorithm. With this system, the access control becomes more security and manageable, the proposed system is cost efficient and is successfully used in some companies.

Abstract: A high performance full adder circuit with full voltage-swing based on a novel 7-transistor xor-xnor cell is proposed in this paper. In our design, we exploit a novel 7-transistor xor-xnor circuit with a signal level restorer in a feedback path to settle the threshold voltage loss problem. Then we present a new high-performance 1-bit full adder based on the designed xor-xnor cell, pass-transistors and transmission gates. The simulation results prove that, compared with other designs in literature, the proposed full adder shows its superiority for less power dissipation, lower critical path delay and smaller power-delay product, and still provides full voltage swing in all nodes of the circuit.

Abstract: A pre-amplifier for distributed track and hold (DTH) circuit in high speed and high resolution folding and interpolating analog-to-digital converter (ADC) is proposed. This scheme resolves several limitations of conventional differential difference pre-amplifier (DDPA) in low voltage supply, compared to the conventional DDPA, the proposed scheme increases the input range so that all DDPAs of DTH can operate effectively, improves the averaging effect of average network, saves the random offset voltage from device mismatch, decreases the gain error of DTH, reduces the output common-mode (CM) deviation of DTH, and enhances the CM rejection of DTH. Based on SMIC 0.18μm CMOS technology and 1.8V power supply, over the input range, results from spectre shows dummy DDPAs of DTH operate effectively, the offset of output CM voltage of DTH decrease to less than 2mV, gain error decrease to less than 1%, the gain of middle novel pre-amplifier and boundary novel pre-amplifier are both 2.5, bandwidths are all above 1.9GHZ, while power dissipation of each DDPA is 3.22mW. The high CM rejection and low gain error decrease the quantification error effectively, and enhance the performance of ADC. The design meets the requirement of ADC applied to software defined radio (SDR).

Abstract: Rogue ONU is a critical failure in TDMA-PON because of the nature that more than one subscribers share upstream bandwidth. A reliable scheme is proposed to detect continuous long light emitting ONUs. And the judge time can be changed by setting the CLK. Compared with other solutions it is cheap and reliable.

Abstract: In this paper, two types of miniaturized dual-mode bandpass filters (BPF), a single-ring (SR) resonator, and a double-ring (DR) resonator are developed. By applying the capacitive-coupling technique to a dual-mode ring filter, a technique is proposed to miniaturize the dual-mode double-ring filter. An adjustable dual-band bandpass filter is achieved by developing a ring resonator where the two modes are capacitively coupled. Control of the filter center frequency is determined by the diameter of the ring and by the rings annular width. Filter coupling amount can also be adjusted by disturbance (perturbation) of an open stub attached to the annular disc. Proposed filters explore both single- and double-ring architectures. A single-ring resonator acting as a dual bandpass filter to allow 3.8 GHz and 7.8 GHz single is developed. A double-ring resonator to allow 2.05 GHz and 3.9 GHz signals is also developed. The ring resonators are fabricated on RO-4003 substrate, with relative dielectric constant of 3.38, thickness of 0.8 mm, and dielectric loss tangent of 0.0025. Results indicate the filters can be applied in the communications field.

Abstract: A miniature vapor-compression refrigeration system for cooling high power CPUs has been developed and tested. The refrigeration system is so small that it can be embedded into the computer case. The refrigerant used in the system is R-134a. The system consists of a miniature rotary DC compressor, a micro-channel condenser, a specially designed cold plate, a short tube restrictor, and related controlling electronics. The compressor is powered directly by the 12V DC power supply of the computer. The cold plate contacts the CPU surface directly and carries away the heat dissipation by conductivity. In a series of tests to cool an Intel Core i7-990X CPU that has 12 cores inside with the refrigeration system, the CPU core temperature can be kept at 23°C in default frequency 3.5GHz and 100% of workload. When the CPU is overclocked to 4.8GHz, the core temperature can be maintained at 59°C. Even when overclocked to 5.0GHz, the core temperature does not exceed 78°C. The test results validate the ability and potential of using vapor-compression refrigeration technology in high heat flux CPU cooling.

Abstract: A series of portable mass storage devices are arising due to the effective support from USB interface for its special features, such as easy to use, a high transfer speed and low price. 8051_USB IP core is to achieve data acquisition and efficient data transfer to PC. The abstract of USB Protocol is introduced firstly. Then the design and verification of 8051_USB IP core are discussed in detail. Modules of 8051_USB protocol controller are designed with Verilog HDL. The design is simulated with Modelsim.

Abstract: Wideband DC Amplifier plays an important role in scientific research and measuring instruments. This paper presents a wideband amplifier with controllable DC voltage gain with a programmable gain amplifier AD600, 12-Bit Serial D / A chip DAC7611 and FPGA-based IP MCS-51 MC as its core. Test results show that the pass band of the whole system is 0Hz ~ 10MHz, the voltage gain ranges from 0dB to 60dB, the gain step is 1dB, the maximum output voltage sine wave RMS Vo ≥ 10V, and there is no significant distortion in the output signal waveform. The system is not only characterized by its high speed, high efficiency, small size and in-built orientation of peripheral circuits, which are the features of MC constructed with a MC with FPGA, but also has advantages of flexible designing, scalability, extensibility and upgradability. Therefore it has good application prospects and research values.