Wojciech Krzysztofik

By Wojciech Jan Krzysztofik

Recently, telecommunication systems have been requiring more advanced features in the design and operation. Among others a smaller size of devices, which can be integrated for multiple mobile communication systems, applied in one user’s device board, such as PDA or smart phone. Moreover, the cost of mass production should be minimized as much as possible. To meet part of that request, the antennas of these devices should have small size, lower weight, operating in multiple frequency bands and/or be broadband. There are many research methods to achieve this goal, one of which is using the fractal geometries for the shape of antenna elements. In recent years, there are many fractal shapes that have been proposed for such applications, and the designed antennas have significantly improved antenna features such as smaller size, operating in multi-frequency bands, with improved power gain and efficiency. In recent years, the new approach for modern antenna the metamaterials, MTM, is adopted, and sometimes that based on the fractal geometry is adopted.

Part of the book: Fractal Analysis

By Wojciech Jan Krzysztofik

As the growing demand for mobile communications is constantly increasing, the need for better coverage, improved capacity, and higher transmission quality rises. Thus, a more efficient use of the radio spectrum and communication systems availability are required. This chapter presents EM propagation models most commonly used for the design of wireless communication systems, computer networks WLAN and WPAN for urban and/or in indoor environments. The review of commercial or University computer codes to assist design of WLAN and WPAN networks were done. An example of computer design and simulation of indoor Bluetooth and WLAN communication systems, in the building of Wroclaw University of Science and Technology, Wroclaw, Poland is shown in Chapter 8.

Part of the book: Antennas and Wave Propagation

By Wojciech Jan Krzysztofik and Thanh Nghia Cao

In recent years, the demand for miniaturization and integration of many functions of telecommunication equipment is of great interest, especially devices that are widely used in life such as mobile communication systems, smart phones, handheld tablets, GPS receivers, wireless Internet devices, etc. To satisfy this requirement, the mobile device components must be compact and capable of multifunction, multifrequency band operation. An antenna is one of them; it means that it must be conformal to the body of device, reduced in size, and capable to operating at multiple frequencies of mobile communication systems that have been operating on one, so-called smart device. Nowadays, there are many technical solutions applied in the antenna construction to satisfy of those requirements. There are microstrip antenna technology miniaturized by means of high-permittivity dielectric substrate, using shorting wall, shorting pins, some deformation, as the fractal geometry is, and others. However, these methods have disadvantage such as narrow bandwidth and low gain. A new solution that is of great interest to designers is the use of electromagnetic metamaterials for antenna design. The use of metamaterials in antenna design not only dramatically reduces the size of the antenna but can also improve other antenna parameters such as enhancing bandwidth, increasing gain, or generating multiband frequencies of antennas operation.

Part of the book: Metamaterials and Metasurfaces