Playing games is not just for children. In fact, playing games can make the learning process easier and more fun for adult students as well, for example, in language courses. Despite this success in teaching other subjects, microwave engineering education rarely employs games for learning. However, during the past few years, we have designed and optimized a game that is suitable for senior undergraduates or first-year graduate students in an introductory microwave engineering course. The game is welcomed by our students and indeed makes both teaching and learning more interesting. In this article, I introduce the design philosophy of the game and explain how to play it.
The aim and goal of this book is to provide scientists and engineers in the fields of antennas, microwaves, and electromagnetics with up-to-date knowledge of reflectarray antenna theory, design, and applications. This text provides the reader who has a grasp of the basics of antenna engineering with an overview of reflectarray antenna research history and current state of the art as well as good knowledge of the basic theories behind the design and analysis of reflectarray antennas, and detailed design procedures for a wide range of diverse and advanced applications. The first part of the book presents the fundamental theory of reflect arrays. The second part of the book is intended for researchers and specialists who have good knowledge of the basic theories of reflectarrays and aim to design reflectarray antennas for specific applications/operations. This book provides much content that is of interest to the antenna engineering research community. Its content is comprehensive and interesting, and it presents novel theories and designs in the field of antennas. From the reviewers' point of view, this book is a good choice for graduatelevel students.
With the rapid development of wireless communication technology, high-performance miniaturized RF circuits are becoming more complicated, and more functions and signals are being packed into a small, tight space, resulting in a significant level of electromagnetic (EM) interference and signal crosstalk. In modern wireless communication systems, a higher signal-to-noise ratio is desirable and can be attained using differential signals and circuits. Using the differential technique, commonmode (CM) interference is rejected, enhancing signal transparency. Thus, lots of attention has been drawn to differential/balanced circuits, owing to their advantages over traditional single-ended circuits, such as immunity to interference, high reliability, considerable output power, harmonic suppression, and so on . Corresponding to this trend, differential topologies have been used to design basic and key devices for RF front-end systems, such as filters , , power dividers , antennas , , and active components .
Advances in wireless communication are propelling the development of microwave applications for smart cities, the Internet of Things, and 5G wireless communications. However, in practice, blockages, such as hands, bodies, and walls, severely limit microwave signal propagation. Thus, good-quality relay systems are highly valuable because they can significantly improve network coverage and system throughput. Relay systems can also save energy by switching operation mode according to the working environment. In this article, a relay transceiver is introduced that was awarded first place in the Adaptive Relay Transceiver Student Design Competition (SDC) during the IEEE Microwave Theory and Techniques Society (MTT-S). 2019 International Microwave Symposium (IMS2019). This competition category was sponsored by MTT-S Technical Coordinating Committee 20.
Modern multistandard wireless systems require reconfigurability for mult iband operat ion; therefore, switchable or reconfigurable frontend filters are in high demand. This article introduces a four-channel switchable filter bank, which was awarded first place in the Four-Channel Switchable/Reconfigurable Filter Bank category of the Student Design Competition (SDC) sponsored by Technical Committee 8 at the 2019 IEEE Microwave Theory and Techniques Society International Microwave Symposium.
The Doherty amplifier, invented by William H. Doherty, has been around since 1936 -. The amplifier has seen a resurgence in recent times, in part due to the work of Steve Cripps . The Doherty?s ability to achieve high efficiency over a wide band of frequencies and its high linearity characteristics make it an effective architecture for applications ranging from telecommunications to cellular base stations to the defense industry. The Doherty amplifier formed the basis of design for the author's entry in the 2019 IEEE Microwave Theory and Techniques Society International Microwave Symposium (IMS2019) High-Efficiency Power Amplifier Student Design Competition (SDC) .
This article reviews the three key concepts of modern microwave-filter synthesis using coupled resonators: coupling matrix (CM), extracted pole (EP), and nonresonating node (NRN). CM synthesis is no doubt the most popular and powerful of the three. EP has been around longer as a circuit-synthesis tool, but it seems to have only limited applications. Both CM and EP were developed before the proliferation of electromagnetic (EM) simulators and fast modern computers. CM is widely used because the simple mapping relationship between the physical dimension of coupling structures and synthesized coupling values is well developed. NRN is the newest concept and has drawn a lot of attention. It is a result of circuit synthesis but can also be expressed using CM/EP.
The rapid development of wireless technologies has created high demand for microwave circuits with compact size, low loss, and high efficiency. Bandpass filters (BPFs) are essential in wireless systems, which are cascaded with many circuits in RF front ends, i.e., power dividers , couplers , switches , and power amplifiers (PAs) . They can be codesigned as multifunctional filtering circuits, including passive and active circuits, to reduce the loss and size of the whole system.
To accommodate growing user demand for faster data rates and extensive connectivity, modern wireless communication systems must evolve to support a sharply increasing number of subscribers, all requesting service at the same time. This trend encourages the broad application of multiple input/multiple output (MIMO) systems. In fact, MIMO techniques can increase data rates, coverage of service areas, and communication reliability without additional RFs. In recent proposals for 5G systems, the required separate RF chains in massive MIMO RF front ends can reach up to 256, with bandwidths of up to 800 MHz per RF chain , . Massive MIMO is a critical technology that helps significantly in increasing network capacity and spectral efficiency, while reducing wireless network interference, ultimately improving the end-user experience.