G. C. Wan

Frequency-coded chipless RFID tag based on spiral resonators

RFID has been widely used around the world and it is necessary and effective to lower the cost of RFID by removing inside chip. A novel frequency-coded chipless RFID tag is presented in this paper. It encodes data into the spectral characteristic by spiral resonators with different structures. The tag with six resonators can produce totally 64 IDs and each tag has its unique ID decided by unique size of spiral resonators. Some experiments have been implemented and the results show that tag has obvious frequency characteristic and can be accurately detected by reader. Results prove that this novel chipless tag has excellent performance in information coding.

First single-dish pulsar observation with 25m radio telescope at Shanghai astronomical observatory

Sheshan station of Shanghai astronomical observatory, China, is equipped with a 25m radio telescope and very-long-baseline-interferometry (VLBI) backend. The first single-dish pulsar observation was implemented with the equipment on April 23, 2010. The observation was made in the L band by using the VLBI backend for data acquisition and the source in the observation was pulsar J0332+5434. After applying an incoherent de-dispersion process to the data and folding according to the period of the source, an average profile was obtained. The observation is the first single-dish observation made with the telescope that produces the correct average profile of the sourcing pulsar.

Intervallic-wavelet analysis for electromagnetic scattering by thin-wire structures

Electromagnetic (EM) scattering by curved thin-wire structures is solved with intervallic wavelets in the method of moments (MoM). The electrical field integral equation (EFIE) for curved thin-wire structures is formulated based on the generalized Pocklingtons integral equation and the unknown current is expanded using the intervallic Coifman father wavelets as basis functions. Since the Coifman wavelets (Coiflets) possess a unique feature, i.e. the vanishing moments which can yield a Dirac-δ-like sampling property, they are used to construct the intervallic wavelets. By using the intervallic wavelets in the MoM and performing a fast wavelet transform (FWT), sparse impedance matrices can be obtained and the drawbacks of dense matrices are overcome. A typical numerical example is presented to demonstrate the effectiveness of the intervallic-wavelet MoM.

Construction and validation for a PSoC wireless transmission system

With the rapid development of intelligent monitoring today, we have applied numerous sensors in monitoring the target area, but the problem of energy consumption has always been difficult to solve. Because of the large number of wireless sensor network node, the supplement of node energy trapped, so its imperative for us to consider the design of low-power system. In this paper, we used the PSoC4 BLE (Bluetooth Low Energy) architecture of CYPRESS corporation to construct a multi-nodes communication network based on the BLE technology and an improved location RSSI (Received Signal Strength Indication) algorithm.

Design of a visualized system for monitoring tunnel's risk based on wireless data transmission

This paper firstly designs a set of tunnel safety pre-warning scheme. According to the detection convergence value and sedimentation value of tunnel section, we judge the safety of the tunnel. Tunnel safety pre-warning scheme can be divided into three broad categories: security, warning and risk. Then, a visualized system for monitoring tunnels risk is followed with the tunnel safety pre-warning scheme. The system is composed of Tunnel Risk acquisition layer, transmission layer and application layer. The security system can judge the safety of the tunnel, and driving the LED lamps of different safety levels. The visualized system, can not only achieve the real-time, online and continuous tunnel monitoring data, but also achieve the function of tunnel safety pre-warning.

An ESD protection design for camera modules

The main components of a cellphone camera are camera lens, color filter, voice-coil motor, motor drive and imaging sensor. Imaging sensor and motor drive both are ESD sensitive COMS semiconductor devices, the camera will lose its efficiency if under protection or operated mistakenly. Common malfunctions are unable to preview, motor fails to focus, I2C communication failure and abnormal heating. Therefore, it is important for researchers in this field to study the camera ESD failure causes, failure mode, failure analysis methods, ESD protection design methods and ESD test and imitation as well as test procedure, the research result is also conducive to further improve the quality of products and to solve various puzzling problems.

A hardware-in-the-loop model and simulation for the braking system of freight trains

The 120-type braking device is an important equipment which offered emergency braking and safety deceleration when train run on tracks. Testing and investigating the performance of 120 air-control valve is a fundamental requirement for the trains safety. Experiment in the real railway operation lines brings lots of inconvenience to the research and development of new products. In order to reduce product research cost and shorten the period of development, in this paper we establish a model and perform simulations for the braking system of a single freight car with the 120-type air-control valve and presents a hardware-in-the-loop implementation for the test stand of braking system. It can simulate running condition of the 120 air-control valve and give the performance parameters.

Design of passive wireless antenna sensors for strain measurement

Metallic dampers in the bridge structures will suffer from a certain degree of deformation leading to a damage or destruction. To assess the deformation of metallic dampers and to decide whether to replace, a passive wireless strain sensor is needed. In this paper, we propose a scheme to design the passive wireless strain measurement system. We first investigate the possibility that a folded patch antenna is used as a strain sensor and then design such a folded patch antenna with a coaxial line feed. We establish a model for the antenna by using the HFSS and perform a series of simulations to find the relationship between the mechanical deformation of antenna and its resonance frequency. With the relationship, the deformation of metallic dampers can be predicted by measuring the resonance frequency shift of the antenna.

A modified CLEAN algorithm for improving aperture synthesis observations of radio astronomy

In the field of radio astronomy, CLEAN algorithm is in constant development. In order to solve the problem of distortion of the image under some conditions, we propose a modified CLEAN algorithm, so that the result map is smooth and the resolution has been improved.

Design of electronic static discharge protection for red-green-blue LED control system in automobiles

As the development of peoples pursuit for driving experience, atmosphere lamp is increasingly used in automobile interior lighting. How to accurately control and change the color of atmosphere light becomes an urgent problem. In addition, any electronic system applying in automobile must go through strict ESD test to make sure that system can work stably in the real environment. In this paper, a RGB LED control system is design to realize the control of color, which uses the arithmetic of additive color mixing to calculate the duty ratio of PWM pulse corresponding to the target color. And some important strategies are adopted for the ESD protection of system and are proved to be effective.