An EMI characterization and modeling study for consumer electronics and integrated circuits

“As internet-of-things (IoT) applications surge, wireless connectivity becomes an essential part of the network. Smart home, one of the most promising application scenarios of IoT, will improve our life quality enormously. However, electromagnetic interference (EMI) to the receiving antenna, either from another electronic product or from a module/an integrated circuit(IC) inside the same wireless device, will degrade the performance of wireless connectivity, thus influencing the user experience. Characterization and modeling of the EMI become increasingly important. In the first part, an improved method to extract equivalent dipoles from magnitude- only electromagnetic-field data based on the genetic algorithm and back-and-forth iteration algorithm is proposed. The method provides an automatic flow to extract the equivalent dipoles from electromagnetic-field data on arbitrarily shaped scanning surfaces and minimizes the number of extracted dipoles. In the second part, both the differential mode (DM) and common mode (CM) EMI below 1 MHz from the ac-dc power supply in a LED TV is analyzed and modeled. Through joint time-frequency analysis, the drain-to-source voltage of the power MOSFET in the power factor correction (PFC) converter is identified as the dominant noise source of both CM and DM EMI below 1 MHz from the power supply. The current paths of DM and CM EMI are explained and modeled by a linear equivalent circuit model. In the last part, the noise source and current path of the conducted CM EMI noise from a Qi-compliant wireless power transfer (WPT) system for mobile applications are analyzed. The analysis and modeling explain the mechanism of the CM EMI noise and provide guidelines to reduce the CM EMI noise”--Abstract, page iv

Near-Field Wireless Power Transfer for 6G Internet of Everything Mobile Networks: Opportunities and Challenges

Radiating wireless power transfer (WPT) brings forth the possibility to cost-efficiently charge wireless devices without requiring a wiring infrastructure. As such, it is expected to play a key role in the deployment of limited-battery communicating devices, as part of the 6G-enabled Internet of Everything (IoE) vision. To date, radiating WPT technologies are mainly studied and designed assuming that the devices are located in the far-field region of the power radiating antenna, resulting in relatively low energy transfer efficiency. However, with the transition of 6G systems to mmWave frequencies combined with the use of large-scale antennas, future WPT devices are likely to operate in the radiating near-field (Fresnel) region. In this article, we provide an overview of the opportunities and challenges that arise from radiating near-field WPT. In particular, we discuss the possibility to realize beam focusing in near-field radiating conditions, and highlight its possible implications for WPT in future IoE networks. Furthermore, we overview some of the design challenges and research directions that arise from this emerging paradigm, including its simultaneous operation with wireless communications, radiating waveform considerations, hardware aspects, and operation with typical antenna architectures

Analysis of Antenna Designs for the Maximum Power Transmission

Since Nikola Tesla discovered wireless power transmission, it has become a very interesting topic of study in the antennas and wireless propagation community. Various aspects and applications for wireless power transmission are studied today, a few of which are investigated in this work. First, various antenna geometries are analyzed for radiative near-field wireless power transfer in terms of electrical field strength. It is determined that the meander antenna is ideal for maximum power transfer in its radiative near-field region, contrary to its far-field behavior. Next, in the application of radio frequency identification, a directive, UHF RFID tag antenna is designed for pavement embedded applications. The antenna covers 72% of the US required bandwidth (902 – 928 MHz) in measurement and has maximum directivity and read range of 7.38 dBi and 14.2ft (4.3 m), respectively. Although the transmitter and receiver antennas\u27 designs are essential parts of the wireless system, power loss to the wireless channel is another critical factor to consider in ensuring the receiver antenna receives the maximum power. Friis transmission equation is studied in detail, and a section of the Georgia Southern University campus is considered for full cellular coverage in the GSM frequency range. Additionally, using the genetic algorithm in parallel, the optimal position for a 60-GHz wireless router is determined to obtain maximum WIFI coverage in a specific house. Finally, the design procedure for a size-reduced, 15-element Yagi antenna is discussed. A comprehensive comparison is conducted demonstrating the importance of the antenna design, with its similar performance to the full-sized Yagi antenna, while its elements are reduced by 45%

Antenna integration for wireless and sensing applications

As integrated circuits become smaller in size, antenna design has become the size limiting factor for RF front ends. The size reduction of an antenna is limited due to tradeoffs between its size and its performance. Thus, combining antenna designs with other system components can reutilize parts of the system and significantly reduce its overall size. The biggest challenge is in minimizing the interference between the antenna and other components so that the radiation performance is not compromised. This is especially true for antenna arrays where the radiation pattern is important. Antenna size reduction is also desired for wireless sensors where the devices need to be unnoticeable to the subjects being monitored. In addition to reducing the interference between components, the environmental effect on the antenna needs to be considered based on sensors' deployment. This dissertation focuses on solving the two challenges: 1) designing compact multi-frequency arrays that maintain directive radiation across their operating bands and 2) developing integrated antennas for sensors that are protected against hazardous environmental conditions. The first part of the dissertation addresses various multi-frequency directive antennas arrays that can be used for base stations, aerospace/satellite applications. A cognitive radio base station antenna that maintains a consistent radiation pattern across the operating frequencies is introduced. This is followed by multi-frequency phased array designs that emphasize light-weight and compactness for aerospace applications. The size and weight of the antenna element is reduced by using paper-based electronics and internal cavity structures. The second part of the dissertation addresses antenna designs for sensor systems such as wireless sensor networks and RFID-based sensors. Solar cell integrated antennas for wireless sensor nodes are introduced to overcome the mechanical weakness posed by conventional monopole designs. This can significantly improve the sturdiness of the sensor from environmental hazards. The dissertation also introduces RFID-based strain sensors as a low-cost solution to massive sensor deployments. With an antenna acting as both the sensing device as well as the communication medium, the cost of an RFID sensor is dramatically reduced. Sensors' strain sensitivities are measured and theoretically derived. Their environmental sensitivities are also investigated to calibrate them for real world applications.Ph.D.Committee Chair: Tentzeris, Emmanouil; Committee Member: Akyildiz, Ian; Committee Member: Allen, Mark; Committee Member: Naishadham, Krishna; Committee Member: Peterson, Andrew; Committee Member: Wang, Yan

Antennas and Propagation

This Special Issue gathers topics of utmost interest in the field of antennas and propagation, such as: new directions and challenges in antenna design and propagation; innovative antenna technologies for space applications; metamaterial, metasurface and other periodic structures; antennas for 5G; electromagnetic field measurements and remote sensing applications

Design and development of multiband antennas for unmanned aerial vehicles (UAVs)

Abstract. This thesis aims to design and analyze microstrip patch antennas for unmanned aerial vehicles (UAVs) for Internet of Things (IoT) communication. With the growing need for reliable and efficient communication in UAV, understanding the unique challenges and requirements of antenna design for UAV-based communication systems becomes crucial. During the process of antenna integration onto the UAV body, important attention must be given to vital factors including the availability of mounting space, weight limitations, and radiation parameters. In this study, extensive efforts were made in the design of the antenna to meet the specific requirements for UAV applications. The antenna structure chosen was a microstrip patch antenna with an inset feed technique. The design aimed at optimizing the antenna for multi-band operation, ensuring compatibility with various communication frequencies. Careful considerations were made regarding size, weight, and functionality to ensure the antenna’s suitability for UAV applications. The first part of the thesis introduces the antenna theory, highlighting significant parameters such as radiation pattern, gain, and efficiency, which are crucial for UAV antenna design. The methodology for selecting various parameters is explained, and the radiation pattern and gain of two commercially available antennas were measured in the SATIMO chamber as a benchmark. The fabricated microstrip patch antenna was also tested both with and without the presence of a UAV to examine the impact of the UAV’s body on its performance. The designed antenna demonstrated a semi-omnidirectional pattern at sub-gigahertz frequencies, achieving a gain value exceeding 6 dBi, thereby fulfilling the requirements for UAV applications. The second part of this thesis focused on further advancements in the design process. Efforts were made to improve the antenna’s performance and behavior through various design modifications and optimizations. The design process involved iterative steps, such as adjusting the dimensions and parameters of the antenna to enhance its performance metrics. The results obtained demonstrated notable improvements in terms of radiation patterns with 92 degree of 3 dB angular beamwidth, gain enhancement up to 6.7 dBi, and overall antenna performance. These findings contribute to the body of knowledge in UAV antenna design and highlight the potential for further advancements in this field

1-D broadside-radiating leaky-wave antenna based on a numerically synthesized impedance surface

A newly-developed deterministic numerical technique for the automated design of metasurface antennas is applied here for the first time to the design of a 1-D printed Leaky-Wave Antenna (LWA) for broadside radiation. The surface impedance synthesis process does not require any a priori knowledge on the impedance pattern, and starts from a mask constraint on the desired far-field and practical bounds on the unit cell impedance values. The designed reactance surface for broadside radiation exhibits a non conventional patterning; this highlights the merit of using an automated design process for a design well known to be challenging for analytical methods. The antenna is physically implemented with an array of metal strips with varying gap widths and simulation results show very good agreement with the predicted performance