Author

Mohamad Kamal A Rahim & Farid Zubir

Description

This edited book serves as a comprehensive resource, providing an overview of reconfigurable antennas for researchers, academicians, and industries. Reconfigurable antennas are classfied into three primary categories, namely frequency, polarization, and pattern, with specific applications in wireless communication systems. The book is organized into multiple chapters, offering a detailed exploration of various reconfigurable techniques for wireless systems. It begins with an introductory chapter that provides an overview of reconfigurable antennas. Subsequent chapters cover topics such as multiband and wideband frequency reconfigurability, reconfigurable metamaterial structures, and the reconfigurability of frequency-selective surfaces.

Additional chapters delve into specific applications, such as the utilization of the reconfigurable antenna with Kapton in smart antenna systems, the frequency reconfigurability of the slotted loop type of antenna, and the frequency aspects of radiation patterns. Furthermore, the book discusses beam scanning arrays utilizing PIN diodes for reflectarray antennas and the polarization reconfigurability of antennas using a PIN diode. The final chapter focuses on the implementation of the Sierpinski gasket fractal on a coplanar waveguide. Through these diverse chapters, the book offers comprehensive insights into the concept and applications of reconfigurable antennas in wireless systems, presenting valuable knowledge for researchers, academicians, and professionals in the field.

Author

Mursyidul Idzam Sabran, Sharul Kamal Abdul Rahim & Siti Fatimah Ausordin

Description

The book focuses on the design of a compact and miniature RF front-end structure operating within a 2.45 GHz unlicensed ISM band for WPT applications. WPT components are composed of five essential elements: antenna, pre-filter, rectifier, post-filter and load. Emphasis will be given only on designing the antenna and filter towards the compactness feature for the WPT application. Several selected design methods are used to achieve compactness with acceptable performances. The chosen approaches are studied to occupy the compact antenna and filter structures. The proposed antennas and filters are simulated and optimized using Computer Simulation Technology (CST) based on the required performances. The optimum design is fabricated and measured in terms of the S11, radiation pattern, gain and AR.

Book Title: High-Frequency Inductive Energy Transfer: Link Enhancement Through Coupling Modification

Author

Akaa Agbee Eteng, Sharul Kamal Abdul Rahim & Siti Fatimah Ausordin

Description

A paucity of broad methodologies for designing inductive energy transfer links has led to the utilization of proprietary and non-interoperable link performance enhancements. The original contribution of this book is the development of general coupling-based design methods to improve the energy transfer performance of high-frequency inductive links. First, the book develops a general procedure to improve the transfer efficiency of symmetric inductive links established using axially-aligned printed spiral coils (PSCs), which are externally constrained by an upper-quality factor bound. The procedure compensates for low PSC quality factors by geometrically improving PSC coupling potentials. The application of the method in a test scenario led to the enhancement of the link transfer efficiency and augmented the link fractional bandwidth without altering the PSC quality factors. Secondly, the book proposes an unobtrusive method for ensuring uniform link transfer efficiency under various degrees of partial lateral misalignment between coupled PSC terminals. The method functions by ensuring that the link operates within an over-coupled regime, irrespective of the alignment conditions. Testing the developed procedure in a design scenario led to a reduction in the range of transfer efficiency values. Finally, a PSC-design technique to enable fixed-matched inductive links to maintain a near constant performance level for distances within a designated operational range. The method is based on seeking to maintain link critical coupling despite having PSC  separation  distances  closer  than  the  designated  link  range.

Author

Muhammad Zairil Muhammad Nor & Sharul Kamal Abdul Rahim 

Description

Antenna reconfigurability features can allow an antenna to make selection and advancement in their operating frequency, polarization, radiation patterns, and gain. The integration of RF switches in the antenna, the reconfigurable antenna allows reconfigurable antenna used in modern wireless applications. In switched-beam reconfigurable antennas, the limitation of conventional antenna which is only able to radiate their radiation pattern at one specific location can be overcome as this type of antenna can switch their main beam at several location by controlling the configuration of their RF switches.

This book describes on the development of a switched-beam reconfigurable antenna by using PIN diodes. There are three phases on developing proposed switched-beam antenna where initiate with development of broad-forward beam printed monopole antenna using FR4 material. Then, the development of patch antenna with defected parabolic ground plane structure has been design in improving the directivity properties of proposed antenna. Lastly, the development of proposed switched-beam reconfigurable antenna where the previous developed antenna will be combined together in array configuration by using parallel strip transmission line technique and implementation of RF switches (PIN diodes) is adapted to transform the proposed antenna into reconfigurable antenna