Hsien-Chiao Teng

Hardware Implementation of RFID Mutual Authentication Protocol

Radio-frequency identification (RFID) is a wireless technology that utilizes radio communication to identify objects with a unique electrical identity. The widespread deployment of RFID technologies may generate new threats to security and user privacy. One of the main drawbacks of RFID technology is the weak authentication systems between a reader and a tag. In general, ¿weak¿ authentication systems that either leak the password directly over the network or leak sufficient information while performing authentication allow intruders to deduce or guess the password. In this paper, we study the RFID tag-reader mutual authentication scheme. A hardware implementation of the mutual authentication protocol for the RFID system is proposed. The proposed system was simulated using Modelsim XE II and synthesized using Xilinx synthesis technology. The system has been successfully implemented in hardware using an Altera DE2 board that included an Altera Cyclone II field-programmable gate array (FPGA). Finally, the output waveforms from the FPGA were displayed on the 16702A logic analysis system for real-time verification.

Design of patch antenna for RFID reader applications

In this paper a single feed circularly polarized patch antenna and a constructed prototype ideal for Gen2 RFID (Generation 2 of Radio frequency identification) reader applications is present. The proposed patch antenna has a simple structure, it have corner truncated square patch, ground plane and a feed line with L-shaped of ground coupled. Through a via hole in the vertical ground of the ground plane, the radiating patch is easily excited by an L-shaped coupled feed oriented in the same plane as the patch, and circular polarization (CP) radiation is achieved. Experimental results of a constructed prototype with the center operating frequency at about 922 MHz showed that the patch antenna has an impedance bandwidth (1.5 ∶ 1 VSWR) of about 10%, return loss S11 of about −26dB and a gain level of 8.5 dB. In addition to the proposed patch antenna due to its simple structure, the obtained CP performance with low cost is among the best that have been reported for single-feed single-element patch antennas.

Study of contact degradation in final testing for BGA socket

BGA socket is most important part in the final testing which selects the good or bad chip of BGA packages. When testing BGA-type packages using a BGA socket, the characteristic contact conditions and mechanisms of surface degradation in a low and stable contact are essential. However, the electrical contact between the pogo pin and the solder ball of the BGA-type package becomes unstable following repeated touchdown operations since particles from the package outline gradually accumulate on the crown tip of pogo pin. The contamination caused by these particles causes the contact resistance to increase. Accordingly, this study develops an experimental procedure for investigating the effect of the particle contamination on the magnitude and stability of the contact resistance. Initially, an experiment is performed to establish the contact resistance between a plated beryllium-copper (BeCu) pin at various number of touchdown. Subsequently, an experiment is conducted to investigate the accumulation of surface particles on the crown tip following multiple touchdowns of the pogo pin with the surface solder ball. The worn-out of crown tip following 6,830 and 36,580 touchdowns, respectively, is examined using a scanning electron microscope (SEM). The experimental results are then integrated to establish a suitable tradeoff between the contact resistance and the number of contacts for the time of socket clean.

A Functional Microstrip Circuit Module for Annular Slot Antenna

A functional microstrip circuit module for annular slot antenna is proposed. This module consists of an annular microstrip line component, two PIN diodes and a DC bias circuit. Reconflgurable circular polarizations can be simply controlled by this functional module. Axial ratio is adjustable by changing the clip angle of the notch made by the annular microstrip line component. Simulated and experimental results have shown good impedance bandwidth for return loss and antenna gains in circularly polarized states.

Planar antennas on flexible substrate for wireless applications

Flex-circuits are a reliable alternative to conventional electronic products. It can offer the same advantages of a printed circuit board: repeatability, reliability, and high density. The design of a planar antenna on a flexible substrate can effectively supersede that of an antenna on a FR-4 substrate for more flexible applications on wireless system integration, such as RFID or Bluetooth link as well as in steering microwave beam.

Basic study of microwave evanescent coupling between parasitic elements on microstrip patch antenna array

The electromagnetic field can be radiated when a signal is transmitted along the radiators on an antenna; meanwhile, evanescent coupling occurs in parasitic elements. This report is demonstrated to characterize grating level displacements of the components and depicts the criterion of evanescent coupling for the design of the microstrip patch antenna array in future to amplify the feed network.

A Functional Antenna Tuner for Slot Patch Antenna

In this paper, without using external power and active components, a design of pin coupled functional antenna tuner is presented. The tuner consists of two parts, a coupling pin and a tuning circuit. It is used to tune the bandwidth and antenna gain of the proposed slot patch antenna. The prototype, including a slot patch antenna and the tuner, was constructed and excited through a T-shape microstrip feed circuit resonated at 2.6GHz. The impedance bandwidth BW (i10dB return loss) of the slot patch antenna without coupling to the tuner was 3% referred to the operation frequency at 2.6GHz. When the tuner was matched with the impedance 75› through the coupling pin to the proposed antenna, the BW of the antenna was increased to 11% operated at 2.6GHz. However, if the tuner was matched with the impedance 25› to the proposed slot patch antenna, the impedance bandwidth of the antenna was increased 21% at operation frequency. Relatively uniform antenna gain was obtained when the matching impedance was decreased from 75› to 20›. In the meantime, the lower matching impedance corresponds to more reducing cross-polarization of the proposed slot patch antenna can be observed in the measured fleld patterns.

The EMI study of organic Alq 3 thin film parasitic

An organic semiconductor thin film of Alq3 coating to a referenced microstrip patch antenna for lowering EMI is demonstrated in this report. Results of the measurements lead to the conclusion that the Alq3 thin film capacitive coupling parasitic influences the antenna gain significantly with little shift of operation frequency at 5.2GHz.

Design of organic Alq3 thin film parasitic patch for the microstrip antenna

The use of organic semiconductor thin film of Alq3 to design parasitic capacitance coupling parasitic for a referenced circularly polarized microstrip patch antenna is demonstrated in this report. Results of the measurements lead to the conclusion that the Alq3 thin film capacitive coupling parasitic influences the circularly polarization significantly with little shift of operation frequency.

The optimal floor plan design for RF application

The proposed automated system enables simultaneously considering the multi-objective effect to forecast or generate a floor plan design for an embedded passive multilayer substrate for RF application. The auto-generated floor plan design for multilayer substrate is demonstrated to have the capability to meet the custom request multi-objective criterion based on the initial users define weighting factor.