Smart antenna beamforming network

Smart Antenna with RF beamforming capability can greatly improve the performance of the vehicle communication system by providing better link quality and high immunity to interference. Butler Matrix is a well-known beamforming network. It can be used for multibeam antennas. The Butler Matrix increases the system capacity and provides higher signal to interference ratio, consequently enhancing the overall system performance. Several studies have been conducted related to the cascading Butler Matrix. In an Multi Port Amplifier (MPA) application, a signal entering one port of the Butler Matrix is divided into equal parts. The signal is then amplified by all the amplifiers and then recombined by the combining Butler Matrix at the output port that corresponds to the particular input port.Suarez also reported that the introduction of the cascading Butler Matrices improves the performance of antenna parameters such as cross over and beam orthogonality

A wideband trapezoidal dielectric resonator antenna with circular polarization

A new design of a circularly-polarized (CP) trapezoidal dielectric resonator antenna (DRA) for wideband wireless application is presented. A single-layered feed is used to excite the trapezoidal shaped dielectric resonator to increase resonant frequency and axial ratio. Besides its structure simplicity, ease of fabrication and low-cost, the proposed antenna features good measured impedance bandwidth, 87.3% at 4.21 GHz to 10.72 GHz frequency bands. Moreover, the antenna also produces 3-dB axial ratio bandwidth of about 710 MHz from 5.17 GHz to 5.88 GHz. The overall size of DRA is 21 mm × 35 mm, which is suitable for mobile devices. Parametric study and measurement results are presented and discussed. Very good agreement is demonstrated between simulated and measured results

A band notch rectangular patch UWB antenna with time domain analysis

Design and construction of band notch microstrip Ultra-wideband (UWB) antenna is proposed. As the WLAN 802.11a operates ranging from 5.15GHz to 5.35GHz and 5.725GHz to 5.825GHz. In contrast, HIPERLAN/2 operates ranging from 5.15GHz to 5.35GHz and 5.47GHz to 5.725GHz. Therefore, a band notched filter is required in order to reduce potential interferences between the UWB antenna and WLAN or HIPERLAN/2 bands. The proposed UWB antenna has capability of notching these operating frequencies approximately around 5GHz to 6GHz. The antenna parameters in frequency domain analysis have been investigated to show its capability as an effective radiating element. Furthermore, time domain Gaussian pulse excitation analysis in UWB systems is also demonstrated in this paper. As a result, the simulation results demonstrated reasonable agreement with the measurement results and good band notched ultra-wideband linear transmission performance has also been achieved in time domain

Active RFID Technology for Asset Tracking and Management System

 Asset is one of valuable item in the industry or institution, missing or lose of asset may have problem in asset management system. The advantages of Radio Frequency Identification (RFID) technology have made this technology useful for asset management and tracking system. The use of active RFID technology for asset tracking is by attaching the tag at the asset or item with assigned a unique ID for identification. A few of active RFID readers install at strategic points or location to track asset movement and collect information when anyone of item pass by in reader coverage area, reader collect information with in reading range and send to backend system. Integration every single system by using wires or wireless methods to keep centralize data processing system. Alert message will be send to representative department to give warning. This asset tracking and management system that use active type of RFID technology is working at ISM band frequency of 433 MHz. The backend systems consist of application software, middleware and database. All the information have been sent from every single system recorded in one central database

UHF RFID Tag Antenna for Vehicle License Plate Number (e-Plate)

 In this research presents a new design of UHF RFID tag antenna for vehicle license plate number (e-plate). The proposed e-plate does not require another gadget or equipment since every vehicle is attached with a vehicle registration plate number and this e-plate embedded together. A low cost FR4 material has been used for its fabrication and there is performance improvement compared to the current tag antenna. The proposed antenna design works at 902-928 MHz frequency band for UHF RFID application with 3.8 dBi antenna gain. The antenna is rectangular in shape and has a dimension of 300 mm x 100 mm, which is usually the typical size of the conventional vehicle registration plate number. Acceptable responses were obtained in simulation at centre frequency of 915 MHz with reflection coefficient of -57.7 dB.  The performance of proposed e-plate antenna was further tested by attaching a RFID tag chip and embedded it to the actual vehicle plate number. Initial testing on the field by attached e-plate on vehicle was achieved maximum reading range of up to 12 meters

A multi band mini printed omni directional antenna with v-shaped for RFID applications

This paper presents a mini multi-band printed omni-directional antenna with v-shaped structure for radio frequency identification (RFID) applications. The proposed multi-band antenna is developed from the initial v-shaped design which is only capable of working as a single-band antenna. By deploying a concept of dipole antenna to an initial design, the proposed antenna is accomplished to operate with two different modes of RFID system which are passive and active modes at frequencies of 915MHz and 2.45 GHz respectively. The passive RFID tag is invented when a chip of Ultra High Frequency (UHF) is integrated with a proposed multi-band antenna. This passive tag, which is able to radiate with the measured signal strength, shows that the reading ranges are boosted almost two times compared to the conventional inlay antenna. The maximum reading range of passive RFID tag with inlay antenna is 5 m, though a reading range up to 10m is achievable through the deployment of the proposed antenna at a measurement field. Implicitly, the measurements carried out on the antenna are in good agreement with the simulated values. Moreover, the size of the mobile passive RFID tag has been substantially as 100mm × 70 mm, even though the antenna is fabricated with an inexpensive FR-4 substrate material. With the reasonable gain, coupled with cheaper material and smaller size, the proposed antenna has attractive potentials for use in RFID applications with multiple frequency antenna for active and passive tags

Multi-Sensor System for Land and Forest Fire Detection Application in Peatland Area

Forest fire has a dangerous impact on environments and humans because of haze and carbon emitted from it. A common technology to detect fire hotspots is to use satellite images and then process them to determine the number of hotspots and their location. However, satellite systems cannot penetrate in bad weather or cloudy condition. This research proposes a ground sensor system, which uses several sensors related to the indicators of fire, especially fire in peatland area with unique characteristics. Common parameters of fire, such as temperature, smoke, haze, and carbon dioxide, are applied in this system. Indicators are measured using special sensors. Results of every sensor are analyzed by implementing intelligent computer programming, and an algorithm to determine fire hotspots and locations is applied. The fire hotspot location and intensity determined by integrated multiple sensors are more accurate than those determined by a single sensor. Data collected from every sensor are kept in a database, and a graph is generated for reporting and recording. In case of sensor readings with parameters, potential of fire and hotspots detected can be forwarded to the representative department for corresponding actions

Comparative studies of the rain attenuation predictions for tropical regions

The radio waves propagating through the earth atmosphere will be attenuated due to the presence of atmosphere particles, such as water vapor, water drops and the ice particles. Meanwhile, the atmospheric gases and rain will both absorb and scatter the radio waves, and consequently degrade the performance of the link. The results of various studies conducted in temperate and tropical regions have been published in research papers. This paper presents the summary of comparative studies on different rain attenuation prediction methods for terrestrial microwave links tropical regions. Basically the models described in this paper include those of the ITU-R, revised Moupfouma, revised Silva Mello and Lin model. The objective of this study is to reveal the most suitable rain attenuation prediction model for the Malaysian tropical region. This paper will provide useful information for microwave engineers and researchers in making decision over the choice of most suitable rain attenuation prediction for terrestrial links operating in a tropical region. Even though the ITU-R model underestimates the rain attenuation at higher frequencies, the test results have clearly indicated that it is most suitable for predicting terrestrial rain attenuation in tropical Malaysia, compared to others

A zero-sum game approach for non-orthogonal multiple access systems: legitimate eavesdropper case

In this paper, secure communication in non-orthogonal multiple access (NOMA) downlink system is considered wherein two NOMA users with channel gain difference are paired in each transmission slot. The user with poor channel condition (weak user) is entrusted, while the user with good channel condition (strong user) is a potential eavesdropper. The weak user data can be intercepted by the strong user since the strong user needs to decode the weak user's message for successive interference cancellation operation in NOMA. To impair strong user's eavesdropping capability, weak user's information-bearing signal is merged with an artificial signal (AS). Thus, the eavesdropping process requires extra decoding step at higher power level. The secrecy outage probability of the weak user is derived and provided in closed-form expression. The weak user faces a choice between transmitting the information-bearing signal with the total power and the deploying the AS technique, whereas the strong user can choose whether to eavesdrop the weak user's message or not. To investigate users' power-secrecy tradeoffs, their interactions are modeled as a non-cooperative zero-sum game. The existence of Nash equilibria (NEs) of the proposed game is first analyzed, and pure and mixed-strategy NE profiles are provided. In addition, numerical simulations are conducted to validate the analytical results and to prove that AS-Aided proposed scheme enhances the secrecy performance of NOMA systems while maintaining the NOMA superiority over OMA systems

Development of RFID EPC Gen2 Tag for Multi Access Control System

A Radio Frequency Identification (RFID) use radio waves to identify an object, this technology become useful for the future because of the advantages. Access system using RFID card is commonly used in a building, parking area, housing complex, etc. This paper explore and develop the use of RFID EPC Class1 Gen2 tag for multipurpose access system for   identification and access control, such as personal identity identification, door access control and gate entry permit or access control. With the same tag Identity (ID) user can access many areas. RFID EPC Class1 Gen2 tag working at UHF band 902-928 MHz, this type of tag more suitable for multi access control because of scaterring technique in reading for the tag, as for gate access need longer distance read range. All users ID and information stored at the one central database, every transaction at the controlled were recorded in a control system.DOI:http://dx.doi.org/10.11591/ijece.v3i6.385