Active beamforming network design

This paper describe the design and implementation of multi beam antenna array using active beam forming network for wireless local area networks (WLAN) operating at 2.4 GHz band frequency. In this paper, four beam patterns generated by incorporated a rectangular patch antenna array with active beam forming network using switch line phase shifter. The radiation patterns measurement of multibeam antenna using active beam forming is compared with passive beam forming network using butler matrix. It shows that the multibeam antenna can be produced using this active beam forming network by switching the RF diode towards the required phase shift of the circuit. The comparison between active and passive beamforming have been made and discuss

Implementation of a topographic artificial neural network wind speed prediction model for assessing onshore wind power potential in Sibu, Sarawak

This study presents a topographic machine learning based wind speed prediction model. Predicted and ground station data were used to examine the wind energy potential in Sibu. A terrain-based artificial neural network was developed using MATLAB/Simulink (2016). It was found that the developed model can predict wind speed values in areas where the model was implemented. The detailed wind resource assessment shows that the power and energy densities fall within Class 1, which is suitable for smallscale applications. The annual energy output of the selected wind turbines was found to be 2343.12– 12036.85 kWh/year with an annual capacity factor in the range of 2.16%–7.77%

Measurements and Analysis of Mobile Satellite Signal Performance Using Handheld GPS Receiver

There is need for experimental data in the less developed and developing countries such as Africa, Asia and Latin America for the study and analysis of mobile satellite signal performance for communication purposes. The experiments were carried out in open space area with no obstruction of the direct wave. Comparisons were made between the soft reformatted data obtained in Kano, Kota Samarahan in Sarawak and Fukuoka in Japan. Data acquisition system developments were designed to manage the open space environment satellite propagation data for the less develop regions, whereby adaptive graphical user interface (AGUI) was designed and developed to records the propagations data. Therefore the recorded data will be used to evaluate the signal performance in term of SNR, azimuth angles and satellite elevation angles. Results obtained from analysis will be used to determine the characteristics of the open space environment. This method can be used to encourage more experimental works in the less develop countries. The analysis produced an important part in the studies of the signal performance. The hyper-terminal intercepts and adaptive graphic user interface were used to evaluate the previous data acquisition system conducted in Fukuoka and Stuttgart. The analysis for ionospheric effect on Mobile Satellite (MS) was conducted by comparing data obtained in Kota Samarahan, Kano with the data obtained in Fukuoka Japan. The experimental work was conducted with reduced cost and simple equipments so as to encourage more experimental studies on MS signal performance. Future research studies can be done by designing a program that will link and monitor the pilot data acquisition system placed in remote areas. Rain sensor and satellite display view can be added to the AGUI

External antenna design for GPS signal reception enhancement

The working paper explains the detailed analysis of the low-cost design and implementation of 53.0 × 41.0 mm Single Microstrip Patch Antenna (SMPA) for handheld Global Positioning System (GPS) receiver external use. A Computer Simulation Technology (CST) microwave studio technique was applied, using the dielectric of 5.0 and substrate thickness of 1.6 mm. The SMPA designed for data acquisition application operating on a single frequency on 1.57542 GHz. The antenna gain enhancement and the signal reception have improved the receiver line-of-sight (LOS) for an indoors experimental usage. However, the external antenna gain overcomes raw data quality degradation caused by the internal antenna due to low elevation angle and results in non LO

Microstrip antenna's gain enhancement using left-handed matematerial structure

The design, simulation and fabrication of a left-handed metamaterial (LHM) structure ispresented. The combination of the modified square rectangular Split Ring Resonator (SRR) and the Capacitance Loaded Strip (CLS) were used to obtain the negative value of permeability, µ and the negative permittivity, e. Nicolson-Ross-Wier approach was used to identify the double negative region. A good agreement between simulated and measured results has been achieved. Upon incorporation with a single patch microstrip antenna, the performance of the antenna was improved where the gain of the microstrip antenna was increased up to 4 dB, and its bandwidth widens from 2.9% to 4.98%. These improvements are due to the negative refraction characteristics of the LHM structure that acts as a lens when placed in front of the antenna

Modelling, simulation and analysis of a single rectangular microstrip patch antenna characteristic

To investigated the microstrip patch antennas performance by studying and analyzing its characteristics and parameters that makes the microstrip elements resonates and radiates microwave signals into space

Modelling, simulation and analysis of a single rectangular microstrip patch antenna characteristic

This research investigated the microstrip patch antennas performance by studying and analyzing its characteristics and parameters that makes the microstrip elements resonates and radiates microwave signals into space. the literature, research, analysis and experiments through simulation is done qualitatively, if not quantitatively, to the characteristics of a square or rectangle microstrip antennas

Circular polarized active integrated antenna for transmit and receive

An active antenna with simultaneous transmit and receive function is of increasing interest, as system designers require more complex functions to be implemented in reduced space. This chapter discusses the integration of active antennas by combining both transmit and receive functions into one single antenna. Four main components in the design are circular polarized microstrip patch antenna, rat race coupler, power divider and amplifiers. The simulation of the circuit is done using the Agilent ADS. Each individual components was designed using Agilent ADS, before the components were fabricated. The optimization and the analysis have been done using the software. The circular polarized antenna resonates at 2.4 GHz. Two MESFET amplifiers have been used to transmit and receive the channel separately. The rat race coupler isolates the two channels and a Tee junction power divider is connected the two channels to the input and output port. The channels are of the same frequency. The simulation and measurement results of the microstrip patch antenna for S11 are lower than -10 dB at frequency of 2.4 GHz. The antenna polarization is confirmed as a circular polarized, as can be seen in the radiation pattern from the measured and simulated results. The amplifier biasing circuit is supplied by two power sources; one is the drain voltage (Vds) which is positive and the other is the gate voltage (Vgs), which is negative. When Vgs is fixed at a certain value, the current (Ids) from drain to source will vary while tuning Vds and when Vds is fixed at certain values, Ids will also change, while tuning Vgs. After integrating all of the components such as antenna, coupler, amplifier and divider together, the antenna is measured and implemented for both transmit and receive

Microstrip antenna array and electromagnetic band gap (EBG) structures

Planar and microstrip antennas’ technology has been the most rapidly developing topic and has become a favorite subject of research by many academicians, researchers and engineers throughout the globe. Just like an artist but with an extra understanding on how an antenna works, a plane piece of substrate materials with a thin copper laminates on one or both sides of the substrate gives the designers the freedom to come out with unlimited antenna designs, including methods to improve their performance. It has evolved from academic novelty to commercial reality in the past several decades and is still undergoing monumental developments due to driving factors such as newer requirements set by the latest standards, technologies, government rules and regulations and most importantly, the increasing demands of multifunctional telecommunication devises by users and markets around the globe