Concentrated Ground Plane Booster Antenna Technology for Multiband Operation in Handset Devices

The current demand in the handset antenna field requires multiband antennas due to the existence of multiple communication standards and the emergence of new ones. At the same time, antennas with reduced dimensions are strongly required in order to be easily integrated. In this sense, the paper proposes a compact radiating system that uses two non-resonant elements to properly excite the ground plane to solve the abovementioned shortcomings by minimizing the required Printed Circuit Board (PCB) area while ensuring a multiband performance. These non-resonant elements are called here ground plane boosters since they excite an efficient mode of the ground plane. The proposed radiating system comprises two ground plane boosters of small dimensions of 5 mm x 5 mm x 5 mm. One is in charge of the low frequency region (0.824-0.960 GHz) and the other is in charge of the high frequency region (1.710-2.170 GHz). With the aim of achieving a compact configuration, the two boosters are placed close to each other in a corner of the ground plane of a handset device (concentrated architecture). Several experiments related to the coupling between boosters have been carried out in two different platforms (barphone and smartphone), and the best position and the required matching network are presented. The novel proposal achieves multiband performance at GSM850/900/1800/1900 and UMTS

Numerical synthesis of filtering antennas

Dizertační práce je zaměřena na kompletní metodiku návrhu tří a čtyř prvkových flíčkových anténních řad, které neobsahují žádné filtrující části a přesto se chovají jako filtrující antény (filtény). Návrhová metodika kombinuje přístup pro návrh filtrů s přístupem pro anténní řady a zahrnuje tvarování frekvenčních odezev činitele odrazu a normovaného realizovaného zisku. Směr hlavního laloku přes pracovní pásmo je kontrolován také. S cílem kontrolovat tvary uvedených charakteristik, nové gi koeficienty jsou představeny pro návrh filtrujících anténních řad. Návrhová metodika byla ověřena na tří a čtyř prvkové filtrující anténní řadě přes frekvenční pásmo od 4,8 GHz do 6,8 GHz, pro šířku pásma celé struktury od 7 % do 14 % a pro požadovanou úroveň činitele odrazu od –10 dB do –20 dB. Celá metodika byla podpořena výrobou a měřením šesti testovacích vzorků filtrujících anténních řad s rozdílnými konfiguracemi. Ve všech případech se simulované a naměřené výsledky dobře shodují.The dissertation thesis is focused on a complete design methodology of a three and four-element patch antenna arrays which are without any filtering parts and yet behave like a filtering antenna (filtenna). This design combines filter and antenna approaches and includes shaping the frequency response of the reflection coefficient and the modelling of the frequency response of the normalized realized gain. The frequency response of the main lobe direction is controlled as well. In order to control the shape of these responses, a set of gi coefficients for designing the filtering antenna array are obtained. The design methodology was verified on the three-element and four-element filtennas over the frequency range from 4.8 GHz to 6.8 GHz; for fractional bandwidth from 7 % to 14 % and for level of the reflection coefficient from –10 dB to –20 dB. The whole design methodology was supported by manufacturing and measuring six test cases of the filtering antenna array with different configurations. Simulated and measured results show a good agreement in all cases.

Fractal Array Antennas and Applications

Modern celestial and other advanced wireless communication systems require feasible array antennas with reconfigurable multibeams, broadband, high end of coverage, high gain, less side-lobe level with wider side-lobe level angles, better signal-to-noise ratio and small in size than conventionally achievable. This has initiated array antenna research in different tracks, one of which is by using fractal array antennas. The investigation on fractal-shaped antennas is basically focused on two fundamental areas such as the analysis and design of fractal antenna elements and the application of fractal geometric technology to the design of array antennas. These recursively generated antennas provide new insights into the antenna properties due to their self-similar behaviour. Owing to the feasible geometric construction and advanced properties, fractal antennas find applications in advanced wireless communications, MIMO radars, satellite communications and space observations. This work concentrated here is primarily aimed on the design of fractal array antennas using concentric elliptical ring sub-array fractal geometric design methodology and the reduction of total number of antenna elements at higher expansion factors of both conventional and proposed fractal array antennas

Multiband Antennas Design Techniques for 5G Networks: Present and Future Research Directions

With the development of wireless communication system has demanded compact wireless devices that allow more space to integrate the other electronics components. Advancement in technology creates challenges in implementing antenna for multiple RF band with a wide range of frequencies. With the advancement of optimization technique we can improve the antenna design as well as provide us the motivation of analyzing the existing studies in order to categorize and synthesize them in a meaningful manner. The objective of this paper contributes in two ways. First, it provides the research and development trends and novel approaches in design of multiband MIMO, smart reconfigurable and defected ground structure (DGS) antenna techniques for wireless system. Secondly, it highlights unique design issue reported in literature. The proposed paper aim is filling the gap in the literature and providing the researcher a useful reference

Fractal Antennas for Wireless Communications

When the length of the antenna is less than a quarter of the wavelength of the operating frequency, good radiation properties are difficult to obtain. However, size limitations can be overcome in this case using a fractal geometry antenna. The shape is repeated in a limited size such that the total length of the antenna is increased to match, for example, half of the wavelength of the corresponding desired frequency. Many fractal geometries, e.g., the tree, Koch, Minkowski, and Hilbert fractals, are available. This chapter describes the details of designing, simulations, and experimental measurements of fractal antennas. Based on dimensional geometry in terms of desired frequency bands, the characteristics of each iteration are studied carefully to improve the process of designing the antennas. In depth, the surface current distribution is investigated and analyzed to enhance the circular polarization radiation and axial ratio bandwidth (ARBW). Both, simulation and experimental, results are discussed and compared. Two types of fractal antennas are proposed. The first proposed fractal antenna has a new structure configured via a five-stage process. The second proposed fractal antenna has a low profile, wherein the configuration of the antenna was based on three iterations

Recent Techniques in Design and Implementation of Microwave Planar Filters

This paper details the techniques and initiatives made recently for improved response and simultaneous development of microwave planar filters. Although the objective of all the techniques is to design low cost filters with reduced dimensions, compact size with better frequency response, the methodological approaches are quite variant. The paper has gone through extensive analysis of all these techniques, their concept and design procedures

Bandwidth Optimization of Microstrip Patch Antenna- A Basic Overview

An antenna is a very important device in wireless applications. It converts the electrical energy into RF signal at the transmitter and RF signal into electrical energy at the receiver side. A micro strip antenna consists of a rectangular patch on a ground plane separated by dielectric substrate. The patch in the antenna is made of a conducting material Cu (Copper) or Au (Gold) and this can be in any shape of rectangular, circular, triangular, elliptical or some other common shape. Researches of past few year shows that, various work on Microstrip Patch Antenna is attentive on designing compact sized Microstrip Antenna with efficiency and bandwidth optimized. But inherently Microstrip Patch Antenna have narrow bandwidth so to enhance bandwidth various techniques are engaged. Today’s Communication devices need several applications which require higher bandwidth; such as mobile phones these days are getting thinner and smarter but many applications supported by them require higher bandwidth, so microstrip antenna used for performing this operation should provide wider bandwidth as well as their shape should be more efficient and size should be compact so that it should occupy less space while keeping the size of device as small as possible. In this review paper, a review of different techniques used for bandwidth optimization & various shapes of compact and broadband microstrip patch antenna is given