180 research outputs found

    Dynamic Capacity Enhancement using a Smart Antenna in Mobile Telecommunications Networks

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    This work describes an investigation into the performance of antennas for mobile base station applications and techniques for improving the coverage and capacity within a base station cell. The work starts by tracing the development of mobile systems, both in technical and commercial terms, from the earliest analogue systems to present day broadband systems and includes anticipated future developments. This is followed by an outline of how smart antenna systems can be utilised to improve cell coverage and capacity. A novel smart antenna system incorporating an array of slant ± 450 dual- polarised stacked patch elements four columns wide excited by a novel multi-beam forming and beam shaping network has been designed, simulated and implemented. It is found that for an ideal smart antenna array, four narrow overlapping beams, one wide “broadcast channel” beam and right and left shaped beams can be provided. Results are presented for the simulation of the smart antenna system using CST EM simulation software which inherently includes mutual coupling and the effects of a truncated ground plane on the element patterns. The results show some significant changes to the desired set of coverage patterns and various mutual coupling compensation techniques have been reviewed. An improved design technique has been developed for compensating the performance degrading effects of mutual coupling and finite ground plane dimensions in microstrip antenna arrays. The improved technique utilises combination of two previously known techniques: complex excitation weights compensation by inversion of the array mutual coupling scattering matrix and the incorporation of a WAIM (wide angle impedance matching) sheet. The technique has been applied to a novel multi-beam smart antenna array to demonstrate the efficacy of the technique by electromagnetic simulation. In addition, a demonstrator array has been constructed and tested which has yielded a positive conformation of the simulation results. For the developed demonstrator array which provides seven different beams, beams “footprints” have been predicted both for free space propagation and for urban propagation to evaluate the dynamic capacity performance of the smart antenna in a 3G mobile network. The results indicate that sector capacity can be dynamically tailored to user demand profiles by selection of the appropriate beam patterns provided by the novel smart antenna system

    Antenna design for switched-beam system for 3g mobile phone

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    Dynamic capacity enhancement using a smart antenna in mobile telecommunications networks

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    This work describes an investigation into the performance of antennas for mobile base station applications and techniques for improving the coverage and capacity within a base station cell. The work starts by tracing the development of mobile systems, both in technical and commercial terms, from the earliest analogue systems to present day broadband systems and includes anticipated future developments. This is followed by an outline of how smart antenna systems can be utilised to improve cell coverage and capacity. A novel smart antenna system incorporating an array of slant ± 450 dual- polarised stacked patch elements four columns wide excited by a novel multi-beam forming and beam shaping network has been designed, simulated and implemented. It is found that for an ideal smart antenna array, four narrow overlapping beams, one wide “broadcast channel” beam and right and left shaped beams can be provided. Results are presented for the simulation of the smart antenna system using CST EM simulation software which inherently includes mutual coupling and the effects of a truncated ground plane on the element patterns. The results show some significant changes to the desired set of coverage patterns and various mutual coupling compensation techniques have been reviewed. An improved design technique has been developed for compensating the performance degrading effects of mutual coupling and finite ground plane dimensions in microstrip antenna arrays. The improved technique utilises combination of two previously known techniques: complex excitation weights compensation by inversion of the array mutual coupling scattering matrix and the incorporation of a WAIM (wide angle impedance matching) sheet. The technique has been applied to a novel multi-beam smart antenna array to demonstrate the efficacy of the technique by electromagnetic simulation. In addition, a demonstrator array has been constructed and tested which has yielded a positive conformation of the simulation results. For the developed demonstrator array which provides seven different beams, beams “footprints” have been predicted both for free space propagation and for urban propagation to evaluate the dynamic capacity performance of the smart antenna in a 3G mobile network. The results indicate that sector capacity can be dynamically tailored to user demand profiles by selection of the appropriate beam patterns provided by the novel smart antenna system.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Compact Beam-Steerable Antenna Array with Two Passive Parasitic Elements for 5G Mobile Terminals at 28 GHz

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    Evolution and Move toward Fifth-Generation Antenna

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    With the introduction of various antennas in the field of antenna technology, most of the constraints related to the transmission and receiving of the signals at different intervals have been resolved. By the rapid growth in industry and consequently high demands in the communication arena, the conventional antennas are unable to respond to these extended requirements. However, those initial antennas were suitably used in the field of technology. In the recent decades, by introducing new antenna technologies such as metamaterial structures, substrate integrated waveguide (SIW) structures and microstrip antennas with various feeding networks could meet the demands of the current systems. As stated before, in the frequency ranges of below 30 GHz, antenna size and bandwidth are of the important issues, so that novel antennas can be created in low frequencies, which are able to achieve reliable radiation properties when combined with new multiband antennas. Generally, transmission lines are practical in low frequencies and short distances, while higher frequencies are mainly used due to bandwidth goals. This chapter is organized into three subsections related to the 5G wireless communication systems: antennas below 15 GHz or accordingly antennas with wavelength less than 1/20; antennas operating between 15 and 30 GHz; higher frequency antennas or millimeter-wave antennas, which are desired for above 40 GHz

    Statistical Review Evaluation of 5G Antenna Design Models from a Pragmatic Perspective under Multi-Domain Application Scenarios

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    Antenna design for the 5G spectrum requires analysis of contextual frequency bands, design of miniaturization techniques, gain improvement models, polarization techniques, standard radiation pattern designs, metamaterial integration, and substrate selection. Most of these models also vary in terms of qualitative & and quantitative parameters, which include forward gain levels, reverse gain, frequency response, substrate types, antenna shape, feeding levels, etc. Due to such a wide variety in performance, it is ambiguous for researchers to identify the optimum models for their application-specific use cases. This ambiguity results in validating these models on multiple simulation tools, which increases design delays and the cost of deployments. To reduce this ambiguity, a survey of recently proposed antenna design models is discussed in this text. This discussion recommended that polarization optimization and gain maximization are the major impact factors that must be considered while designing antennas. It is also recommended that collocated microstrip slot antennas, fully planar dual-polarized broadband antennas, and real-time deployments of combined slot antenna pairs with wide-band decoupling are very advantageous. Based on this discussion, researchers will be able to identify optimal performance-specific models for different applications. This discussion also compares underlying models in terms of their quantitative parameters, which include forward gain levels, bandwidth, complexity of deployment, scalability, and cost metrics. Upon referring to this comparison, researchers will be able to identify the optimum models for their performance-specific use cases. This review also formulates a novel Antenna Design Rank Metric (ADRM) that combines the evaluated parameters, thereby allowing readers to identify antenna design models that are optimized for multiple parameters and can be used for large-scale 5G communication scenarios

    Mapping of construction waste for eco-costs per value ratio (EVR) index using Google My Maps in Shah Alam, Malaysia

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    Construction waste is one of the major challenges faced in our world today. The residential, commercial and infrastructure industries in Malaysia are recognised as rapidly growing sectors that indirectly bring economic growth to our country. However, the generation of waste in the construction industry is increasing in proportion to the development of new construction. This increase has resulted in negative environmental impacts. To address these issues, the present study focused on the mapping of construction waste generation in low-rise residential construction sites in Shah Alam district, Selangor, using the Google My Maps application. Information on construction waste generation data such as coordinates, photos, types of materials, types of waste, quantity of waste, gross floor area, labour cost, material life-spans and eco-costing per value ratio (EVR) index for monitoring was gathered manually through case studies and site observations over 14 months - the contract period. The collected data was inserted into Google My Maps and AppSheet for the mapping process. The findings of this analysis were based on five selected sample sites in Shah Alam that were under construction from 2013 to 2017. The results identified a total of nine types of construction waste, i.e. rebar and BRC, concrete grade 25, timber formwork, bricks, plaster cement, tiles, drywall, metal deck roofing and ceiling. These types of waste accounted for varying values of the EVR index in the construction projects during the contract period. The system proposed by this study will help to monitor the total construction waste generated from the start of a project and will potentially result in the reduction of construction waste, thereby contributing to sustainable construction

    Switchable dielectric resonator antenna array for fifth generation applications

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    A new generation in telecommunication technology has evolved into 5G. Due to its shorter wavelength compared to the previous generation, this technology requires a wide bandwidth and high gain antenna to compensate for the added losses at a higher frequency. Therefore, a phased array capable of steering the direction of beam with high gain can be used to recover any additional losses. A dielectric resonator (DR) with a dielectric constant of 10 is used in the phased array antenna design and integrated on Rogers/RT Duroid 5880 with a conductor coating of 17.5 Âĩm, a thickness of 0.254 mm, dielectric constant, of 2.2 and loss tangent, of 0.001. All designs are simulated using Ansoft High Frequency Structural Simulator (HFSS) and the numerical analysis involved is done by using MATLAB. The performance of the reflection coefficient and the bandwidth of the fabricated antenna are verified using Vector Network Analyzer (VNA) while the radiation pattern and the antenna gain are tested in an anechoic chamber. The proposed switchable dielectric resonator antenna (DRA) array at 15 GHz is formed through three design stages. The first stage is formed by a single element DRA placed on the ground plane and fed through a narrow aperture. The impedance bandwidth achievable is 2.5 GHz for DRA excited in mode compared to 1.8 GHz for DRA excited in mode. Besides, the gain of the antenna has improved approximately by 10 dBi in comparison to 5.6 dBi when it was excited in mode.Then, a design is formed using three elements of DR named as DRA sub-array design. The driven DR at port 1 is fed by radio frequency (RF) source and the parasitic DRs at port 2 and 3 are excited by the driven DR through mutual coupling effect. A steerable beam is achieved by switching the termination capacitor on the parasitic elements. Then, two DRA sub-array configurations are designed and named as configuration A and configuration B, respectively. Both configurations are excited by a driven DR in mode while the parasitic DRs for configurations A and B are excited in the modeand mode, respectively. From the observation, configuration B demonstrates improved performance with steering angle and maximum gain of 9.63 dBi. Furthermore, configuration B has a narrower beamwidth compared to configuration A. The final stage design is formed by incorporating configuration B with a combination of two driven DRs using power divider and phase switching. The switchable DRA array achieved a maximum gain and bandwidth of 12.8 dBi and 3.1 GHz, respectively. Moreover, the switchable DRA array is able to steer at three various steering angles which are 0 , -30 and +30 with 3 dB beamwidth around 24 by using only 2 ports. Hence, the switchable DRA array is capable to cover 60 sector which is considered suitable for 5G application
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