M.S.R. Shah

Smart Attendance System by suing RFID

The paper describes the development smart attendance system (SAS) that will take an attendance by using information extracted from the RFID database handling system. In order to have complete system functionality, smart attendance system is needed to integrate with RFID database handling system. SAS will fetch the appropriate data from RFID database in order to execute the attendance taking process. Furthermore, SAS is also equipped with other rich additional modules to help lecturers and students in the class such as notes distribution and reminder.

The study of meander line for microstrip and planar design

In this paper, the meander line antenna (MLA) have been designed to operate at 2.4-GHz for WLAN application. Two different designs of meander line antenna are investigated, without conductor line and with conductor line. Microwave Office software is used for simulation designed process. The antenna is fabricated on a double-sided FR-4 printed circuit board using an etching technique. Then the design has been tested with the Advantest Network Analyzer. The comparison between simulation and measurement results for the return loss and radiation patterns were presented. A bandwidth of 80 MHz and return loss of -37.7 dB were obtained at frequency 2.4 GHz. The gain is comparable to microstrip yagi antenna.

The effect of conductor line to meander line antenna design

In this paper, the meander line antenna have been designed to operate at 2.4-GHz for WLAN application. Two different designs of meander line antenna are investigates, without conductor line and with conductor line. The Microwave Office software is used for simulation design process. The antenna is fabricated on a double-sided FR-4 printed circuit board using an etching technique. Then the design has been tested with the advantest network analyzer. The comparison between simulation and measurement results for the return loss and radiation patterns were presented. A bandwidth of 152 MHz and return loss of -37.7 dB were obtained at frequency 2.4 GHz. The gain is comparable to microstrip yagi antenna.

Dual Linearly Polarized Microstrip Array Antenna

Recently, Multiple Input Multiple Output (MIMO) has become popular research topic among researchers for development of a new wireless communications technology. The system capacity can be increase with deployment of MIMO technique in the communications system. Thus, the used of high frequency bandwidth can be avoid since this method required high cost implementation. High transmitted power also is not required because all transmitted branch will transmit same power in MIMO system. There are three major studies in MIMO which are research on array antenna and adaptive signal processing, research on information theory and coding algorithm and research on MIMO channel propagation (Nirmal et al., 2004). MIMO channel capacity can be increase with the increase of number of transmitter and receiver. When the number of the antennas used is fixed, the channel capacity is related to the spatial correlation and the diversity gain from antenna spacing configuration at 17

Polarization Diversity in Wireless MIMO Systems

This paper presented a simple polarization diversity technique that used in MIMO system. The polarization diversity is achieve by manipulated the antenna polarization between horizontal and vertical plane. The measurements based on receive power in line of sight (LOS) environment. Different types of polarization have been done and all results will be shown and discuss.

Analysis of Angle Diversity in MIMO Channel

This paper present the results and performance of angle diversity for direction of arrival (DOA) setup. The 4times4 Butler matrix was been used at transmitter and receiver sides. The 2times2 rectangular patches have been used as a transmitter and receiver medium for wireless transmission. The operating frequency for this measurement is 2.4 GHz in WLAN application. This paper analyze about DOA and AOA for angle diversity technique.

Dual polarization microstrip patch array antenna

This paper present 3 designs of array antenna from type of inset-fed microstrip patch antenna oriented at 45deg and -45deg. The antennas are capable to generate dual-polarization radiation pattern centered at 45deg and -45deg. Combinations of two patches using quarter-wave impedance matching technique has been used to designs the array antennas operate at 2.4 GHz. The designs are simulated using Microwave Office 2004 and were fabricated on FR4 substrate with a dielectric constant epsivr =4.7, tan sigma =0.019 and thickness =1.6 mm. The simulation and measurement result have been compared. The 3 design 1 times 2 array antennas yield a bandwidth greater than 5%. The gain of the proposed antennas is also stable with operated frequency. The average is achieved 20 dBi for 1 times 4 and 2 times 2 array antenna and 9.5 dBi for 1 times 2 array antenna. The result showed that the combination of more patches in array can improve the return loss and antenna gain performances.

Dual polarization inset-fed microstrip patch antenna

In this letter, the design of inset fed microstrip antenna is proposed at 45deg and -45deg to achieve the optimum performance of the return loss, antenna gains and polarization loss. A design of the broadband dual-polarized microstrip antennas is proposed by using the simply inset feed technique but slant at desired rotation. In most applications, the requirement of propagation can be met with a single patch structure. However, in some cases, sharp beamwidth was required, as well as maintaining a low profile structure, which arise the development of microstrip patch array antennas. Both design of array antennas in this paper were connected using parallel feed quarter- wave transformer impedance matching technique.

Measurement of 2.4 GHz MIMO channel using polarization diversity

This paper presents measurement of 4times4 MIMO channel by using polarization diversity technique at 2.4 GHz. The measurement was carried out in indoor wireless environment and line-of-sight (LOS) condition. A linear polarization antenna was used at the transmitter (Tx) and receiver (Rx) with a distance of 3 meters. The results were compared with power correlation coefficient of different polarization diversity techniques.

4x4 Butler Matrix design by using circular bend

In these paper two types of design 4 times 4 Butler Matrix is design and fabricated on FR-4 board. The design specification is at 2.4 GHz for both of its. The circular bend technique is used. Investigation is about design of compact and usual Butler Matrix. The investigation scope includes the length and width effect of the design. The simulation and fabrication results will be compared and discussed.