151 research outputs found
Review of Microstrip Patch Antenna Array at 6GHz Frequency for Long Term Evolution Applications
An antenna is the interface between radio waves spreading through space and electric flows moving in metal conduits, utilized with a transmitter or collector. In transmission, a radio transmitter supplies an electric flow to the antenna's terminals, and the antenna emanates the vitality from the flow as electromagnetic waves (radio waves). A portion of the hopeful groups for 5G interchanges in the frequency of 4-8 GHz at lower range and 20-50 GHz are in upper range. It is normal that the sending of 5G would be in the right on time of 2020s. In this paper review of microstrip patch antenna array at 6 GHz frequency for long term evolution applications are studied. Microstrip patch antenna array are now very hot topic of research among various researchers
Conception et réalisation d'un récepteur composé de réseau d'antennes YAGI multicouches verticales et de composants en ondes millimétriques
RÉSUMÉ
Les applications en ondes millimétriques telles que les réseaux sans-fils haute vitesse demandent des composants de hautes performances, faibles coûts de revient, modulaires et compacts. Ce mémoire présente la conception d’une chaine de démodulation en ondes millimétriques utilisant le concept du multicouche. Tout d’abord, une antenne Yagi multicouche est proposée et démontrée à 5.8 GHz. La structure utilise pour la première fois les éléments parasites des antennes Yagi dans une structure de substrats empilés verticalement. Cela permet d’atteindre un gain de 12 dBi. Deux configuration sont présentées : une première basée sur un dipôle et une deuxième basée sur un patch circulaire afin d’avoir une double polarisation. Les résultats mesurés montrent un très bon accord avec les simulations. Basé sur les principes démontrés précédemment, l’antenne est adaptée à 60 GHz, puis un réseau d’antennes Yagi verticales en ondes millimétriques est introduit pour la première fois exploitant les technologies multicouches. Une analyse est faite pour définir les limites du design. L’antenne élément mesurée atteint un gain de 11 dBi. Le réseau 4x4 a une taille 50x50x60 mm3, et atteint un gain mesuré de 18 dBi sur 7% de bande passante. Une autre configuration du réseau utilisant des antennes Yagi inclinées permet d’avoir une réduction des lobes secondaires tout en ayant un impact minimum sur le gain. Les antennes proposées sont d’excellents candidats pour des systèmes intégrés, faibles coûts, demandant une petite empreinte en ondes millimétriques. Finalement, un nouveau six-port double couche utilisant des Guides Intégrés au Substrats (GIS) est présenté et démontré. Celui-ci permet de faire la démodulation QPSK. Son architecture utilise des coupleurs multicouches, fournissant une grande surface de couplage à travers deux fentes ; un déphaseur inédit, large bande composé de deux stubs plan-H et une ligne de référence ; ainsi que de deux diviseurs de puissance. Les simulations et mesures montrent que le circuit fonctionne correctement sur toute la bande V. La démodulation QPSK complète est testée sous le logiciel de simulation ADS et montre les excellentes performances du système.----------ABSTRACT Millimeter wave applications such as high-speed wireless connections require modular, compact-size, low-cost and high-performance systems. In order to realize a complete receiver satisfying those requirements, compact stacked multilayered designs are presented in this thesis. First, high-gain compact stacked multilayered Yagi designs are proposed and demonstrated at 5.8 GHz. The structure makes use for the first time of vertically stacked Yagi-like parasitic director elements that allow easily obtaining a simulated gain of 12 dBi. Two different antenna configurations are presented, one based on dipole geometry for single polarization, and the other on a circular patch to achieve dual polarization. Measured results of the fabricated antenna prototypes are in good agreement with simulated results. Second, based on the above-demonstrated principle, the antenna is redesigned and adapted for 60 GHz applications, and a novel design showing for the first time an array of Yagi elements in millimeter wave stacked structure is presented. An analysis is performed to define the structure limits. The measured element attains 11 dBi of gain. The proposed 4x4 array has a size of 50x50x60 mm3, and reaches a measured gain of 18 dBi over 7% of bandwidth. An alternative configuration of the array using angled Yagi antenna elements allows for a significant improvement of the side lobe level without a visible impact on the gain. The proposed antennas present excellent candidates for integrated low-cost millimeter-wave systems that require small footprint. Third, a novel dual layered six-port front-end circuit using the Substrate Integrated Waveguide (SIW) technology is presented and demonstrated. The six-port architecture makes use of multilayer couplers, providing a wide coupling area through two slots; a new broadband SIW phase shifter composed of two H-plane stub lines and one reference line; and two SIW power dividers. Simulation and measurement results show that the proposed six-port circuit can easily operate at 60 GHz for V-band system applications. The complete QPSK demodulation is tested through the ADS simulation platform to prove the good performances of the designed circuits
Reconfigurable and multi-functional antennas
This thesis describes a research into multi-frequency and filtering antennas. Several novel antennas are presented, each of which addresses a specific issue for future communication systems, in terms of multi-frequency operation, and filtering capability. These antennas seem to be good candidates for implementation in future multiband radios, cognitive radio (CR), and software defined radio (SDR). The filtering antenna provides an additional filtering action which greatly improves the noise performance and reduces the need for filtering circuitry in the RF front end.
Two types of frequency reconfigurable antennas are presented. One is tunable left-handed loop over ground plane and the second is slot-fed reconfigurable patch. The operating frequency of the left handed loop is reconfigured by loading varactor diodes whilst the frequency agility in the patch is achieved by inserting switches in the coupling slot. The length of the slot is altered by activating the switches.
Compact microstrip antennas with filtering capabilities are presented in this thesis. Two filtering antennas are presented. Whilst the first one consists of three edge-coupled patches, the second filtering antenna consists of rectangular patch coupled to two hairpin resonators. The proposed antennas combine radiating and filtering functions by providing good out of band gain suppression
High Gain Planar Antenna Structures for Ka-band Applications
Antennas are an essential part of a communication system as they control a coverage area of the signal. The millimeter wave band has the potential to offer numerous radio applications which require the large bandwidth channels. Due to the current cellular subscribers’ demand of higher data rates, even cellular communication is expected to move in millimeter wave communications at Ka band of 26.5 GHz to 40 GHz. However, millimeter waves are sensitive to the high degree of atmospheric and oxygen absorption losses. This challenge of the millimeter wave communication can be tackled by employing high gain antennas. In addition, modern electronic products require compact handheld devices to offer the user-friendly system as well as capture the market. Therefore, planar antenna structures are apt for these communication systems.
In this thesis, two antenna structures are presented at the Ka band for millimeter wave communications. Initially, four element patch antenna is presented for high gain in the broadside direction. Patch elements are excited using an aperture coupling from 50Ω microstrip line. Air-gap cavity is used to improve the impedance bandwidth of the design. This structure obtains a relatively moderate impedance bandwidth of 4.6%. The proposed four-element patch antenna exhibits a flat gain over an operating band with 13.8 dB gain at the design frequency. The antenna achieves a wide beamwidth of 700 in H plane. In addition, side lobe levels in E and H planes are -14.5 dB and 23 dB respectively. For the second prototype, an Antipodal Fermi-Linear Tapered Slot Antenna (AFLTSA) is presented to achieve the wide impedance bandwidth with high flat gain for endfire radiation. Substrate Integrated waveguide (SIW) technique is utilized to feed the AFLTSA which reduces insertion losses of the structure. Fermi-Dirac distributed curve in conjunction with a linear curve for a tapered slot increases the coupling of the electric field from a substrate integrated waveguide to the tapered slot. Knife edge rectangular corrugation profile is used at edges of AFLTSA in order to reduce the side lobes and cross polarization levels of radiation pattern. The proposed structure achieves the wide impedance bandwidth to support requirements for high data rate channels. Measurement results from a fabricated prototype exhibit a flat gain over an entire operating frequency band with 16.4 dB gain at 28 GHz. The wide impedance bandwidth is achieved with return loss below 15 dB. Proposed structure has low side lobe levels of -13.9 dB in H plane and -19.5 dB in E plane. In addition, it offers a low cross polarization level of -22 dB
Configuration study for a 30 GHz monolithic receive array, volume 1
Gregorian, Cassegrain, and single reflector systems were analyzed in configuration studies for communications satellite receive antennas. Parametric design and performance curves were generated. A preliminary design of each reflector/feed system was derived including radiating elements, beam-former network, beamsteering system, and MMIC module architecture. Performance estimates and component requirements were developed for each design. A recommended design was selected for both the scanning beam and the fixed beam case. Detailed design and performance analysis results are presented for the selected Cassegrain configurations. The final design point is characterized in detail and performance measures evaluated in terms of gain, sidelobe level, noise figure, carrier-to-interference ratio, prime power, and beamsteering. The effects of mutual coupling and excitation errors (including phase and amplitude quantization errors) are evaluated. Mechanical assembly drawings are given for the final design point. Thermal design requirements are addressed in the mechanical design
Q-Band Millimeter-Wave Antennas: An Enabling Technology for MultiGigabit Wireless Backhaul
[EN] The bandwidth demands in mobile communication systems are growing exponentially day by day as the number of users has increased drastically over the last five years. This mobile data explosion, together with the fixed service limitations, requires a new approach to support this increase in bandwidth demand. Solutions based on lower-frequency microwave wireless systems may be able to meet the bandwidth demand in a short term. However, with the small-cell mass deployment requiring total capacities of 1 Gb/s/km2, scalable, multigigabit backhaul systems are required. Millimeter-wave technology fits nicely into these new backhaul scenarios as it provides extended bandwidth for high-capacity links and adaptive throughput rate, which allows efficient and flexible deployment. Besides these advantages, millimeter-wave solutions become even more attractive when the cost of backhaul solutions and the cost of spectrum licenses are factored in. Compared to the cost of laying fiber to a cell base station, which is the only other scalable solution, the millimeter-wave solution becomes the most appropriate approach.The research leading to these results received funding from the European Commission's seventh Framework Programme under grant agreement 288267.Vilar Mateo, R.; Czarny, R.; Lee, ML.; Loiseaux, B.; Sypek, M.; Makowski, M.; Martel, C.... (2014). Q-Band Millimeter-Wave Antennas: An Enabling Technology for MultiGigabit Wireless Backhaul. IEEE Microwave Magazine. 15(4):121-130. https://doi.org/10.1109/MMM.2014.2308769S12113015
C-Band Quasi Yagi Antenna
This thesis is concerned with investigations of types of broadband antenna elements
namely quasi Yagi antenna. This antennas will be fabricated with a dielectric constant
substrate material (FR4 with dielectric constantεr = 5.4), substrate thickness of 1.6mm
and design frequency of 4 GHz. The first part of the thesis deals with the theory behind
microstrip antennas and transmission lines. An introduction to microstrip antennas is
presented, followed by a literature review on microstrip design equations and background
information with regard to microstrip broadband planar antennas. The three most
commonly used broadband planar antennas are illustrated, namely the Microstrip Patch
antenna, quasi Yagi antenna and Tapered Slot Antenna. In contrast to the microstrip
patch, both the arrays of quasi Yagi antenna and the single-element quasi Yagi antenna
radiates at the end-fire direction. As a result, both these antennas can achieve higher gain,
lower side lobes and wider bandwidth compared to the conventional microstrip patch
antenna. The second part of the thesis is concerned with design procedures and
considerations for the antenna. The design for the antennas is aimed at obtaining wider
bandwidth and better radiation patterns. Besides, a sensitivity analysis of the quasi Yagi
antenna with respect to the design parameters is demonstrated in chapter 4 of this thesis.
The simulation of the quasi Yagi is accomplished by using Avanced Design System
(ADS) software. The simulation results showed that the quasi Yagi antenna is able to
achieve at the desired frequency (4 GHz) that is in the C band frequency
High Gain Broadband mm-wave Antennas and Beamforming for Wireless Communication Systems
Generating multi-beams along with having broadband and beam steering capability in the mm-waves band are of crucial importance for diverse applications such as remote piloted vehicles, satellites, collision-avoidance radars, and ultra-wideband communications systems. Besides, the propagation environment at millimeter wave (mm-wave) frequencies—suggested for the next generation of wireless networks (5G)—lends itself to a beamforming structure wherein antenna arrays are required in order to obtain the necessary link budget and to overcome the associated strong attenuation. Therefore, the design of high gain antennas (to focus the directive beam to a user) and beamforming networks (to reduce interference) are essential and are needed to address many challenges associated with 5G wireless communications.
This work addresses the design and development of high-performance Quasi-Yagi antenna and Rotman lens-based beamforming networks. Accordingly, several issues are addressed in this thesis.
A Quasi-Yagi antenna with a perturbed dielectric lens that is broadband and has high gain is designed, optimized, fabricated and tested at 30 GHz. The antenna provides 95% aperture efficiency with a measured gain of 15 dBi as well as a radiation efficiency of ~90% at 30 GHz and a broadband (24-40 GHz) for |S_11 |<-10 dB. The designed end-fire antenna, with its low-profile and compact size, is a good candidate for many applications in the mm-wave band.
An optimum and accurate methodology for designing Rotman lens-based mm-wave analog beamforming network (BFN) is presented. The simulation and measurement results showed good beamforming capabilities as well as a scanning range of 80° in the azimuth plane, and, also, good matching at the array ports. The maximum phase error is ±6.6°, and the main beam of the proposed BFN points at seven different angular directions that cover the range of ±40°. The maximum achieved realized gain is 14 dBi at 28 GHz for the center beam.
An analog Rotman lens-based BFN using RWG technology, integrated with the excitation ports and the antenna array elements, was designed, simulated, manufactured, and measured. The proposed integrated system is realized using the metallized 3D-printing technology, in order to reduce the implementation cost of the full metal RGW Rotman lens. The measured results demonstrate that the system scan range equals ±39.5º over a wideband 27.5-37 GHz decreases to 30º in the band 37-40 GHz. The BFN bandwidth for VSWR < 2 is larger than 38% and is limited by its single antenna element
Microwave Filters Based on New Design Concepts in Several Technologies with Emphasis on the Printed Ridge Gap Waveguide Technology
Microwave filters have been an interesting research topic for more than half a century. Since any communication system is required to use some microwave filters, considerable effort is being made to optimize the performance and size of these filters. As operating frequency is on the rise, filter design becomes more challenging with the demand for low insertion losses and low cost. As low cost might require the use of printed circuit technology, high performance demands waveguide technology that drives the cost to unacceptable levels. There is a need for a new technology that achieves both requirements of low cost and high performance.
The new technology of ridge gap waveguide that was proposed in 2011 shows promising characteristics as a new guiding structure, especially for high-frequency bands. Therefore, it is necessary to design and propose classic or even new filtering devices on this technology. Here, we propose the use of this technology to design practical and efficient microwave filters.
The work of this thesis can be divided into three major parts: (1) Developing efficient codes and methods to optimize the computationally expensive structure of ridge gap waveguide or any other large-scale microwave filter device. (2) Characterizing cavity structures on ridge gap waveguide and using them in the design of simple microwave filters. (3) The third part will discuss more advanced and practical filters, especially using printed ridge gap waveguide technology. The ultimate goal of this thesis is to design and propose state of the art designs in the field of microwave filters that can satisfy the requirements of today’s advanced communication systems and to be cost efficient and compete with other rival technologies. We achieved these objectives using efficient optimization, efficient design techniques, and fabrication of the models using advanced technology
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