Anthony K. Amert

Bio: Anthony K. Amert is an academic researcher from South Dakota School of Mines and Technology. The author has contributed to research in topics: Dielectric & Microstrip antenna. The author has an hindex of 10, co-authored 28 publications receiving 498 citations. Previous affiliations of Anthony K. Amert include Occupational Safety and Health Administration.

A Direct-Write Printed Antenna on Paper-Based Organic Substrate for Flexible Displays and WLAN Applications

Abstract: This paper presents the design, fabrication and measurements of a direct-write printed low-cost and flexible inverted-F antenna on an ultra-low-cost paper-based organic substrate for wireless local area network (WLAN) and flexible display applications. Innovations include the study and utilization of paper as a high-frequency substrate for the first time in the gigahertz (GHz) range, the fabrication technology for the direct-write printing of the antenna as a flexible RF electronic device, and the investigation of antenna flexibility in conjunction with flexible displays. Although paper substrates exhibit relatively high dielectric losses (tanδ ~ 0.065 at 2.45 GHz), the maximum realized gain of the fabricated antenna is measured to be + 1.2 dBi giving a total efficiency ~ 82%. Simulated results of the antenna's return loss and radiation patterns agree well with the measurements, and can lead to a whole new class of flexible low-cost electronic devices of the future.

Bandwidth Enhancement of the Resonant Cavity Antenna by Using Two Dielectric Superstrates

Abstract: We propose a novel approach to enhance the bandwidth of the high directivity of the resonant cavity antenna (RCA) by applying two dielectric layers as superstrates. The approach is based on creating two cavities corresponding to two operating frequency bands that combine to form a single wide band of operation. The RCA design is discussed in a methodological manner to determine the thicknesses of the superstrates, the separation distance between them, and the separation distance to the ground plane. We show that the proposed technique is capable of enhancing the bandwidth from 9% of the single superstrate RCA to 17.9% of the two superstrate RCA, with only 0.1-dB reduction of the maximum directivity (17.5 dBi). The presented design method can be replicated for any RCA with any directivity level and type of primary feeding. The performance of the analytically designed antenna is validated by simulation using commercial numerical electromagnetics software.

Non-aqueous synthesis of silver nanoparticles using tin acetate as a reducing agent for the conductive ink formulation in printed electronics

Abstract: We have developed a process for the synthesis of silver nanoparticles protected with a passivating shell of dodecylamine in toluene media using tin(II) acetate as a reducing agent. Based on the electrochemical series, during the reduction process Sn(II) oxidizes into Sn(IV) which reduces Ag(I) into Ag(0). The nucleation and growth processes result in particles with diameters in the range 5–20 nm. This simple non-aqueous one pot synthesis can be easily scaled up to produce grams of nanoparticles in a matter of hours. The particles can also be dispersed in many non-aqueous solvents which make them a suitable candidate for many applications. Characterization of the end product using TEM, UV-Vis spectroscopy, and powder X-ray diffraction verified the presence of a silver metallic core whereas TGA confirmed the presence of a dodecylamine shell. The resulting particles were used in non-aqueous conductive ink formulation. The ink was used to print conductive tracks on flexible substrates like Epson photo paper and polyimide (Kapton) using an Aerosol Jet based printing technique.

Miniaturization of the Biconical Antenna for Ultrawideband Applications

Abstract: A miniaturized, ultrawideband antenna for the 3.1 to 10.6 GHz frequency band is presented. The antenna is designed to have a low profile to enhance integration onto existing structures and a low directivity pattern for body worn applications. A systematic process to miniaturize the well-known biconical antenna is illustrated by adding several different geometric features that reduce the size of the antenna. After miniaturization, the vertical height of the antenna was reduced by over 60% while maintaining electrical performance. Prototype antennas were manufactured using low cost plastic injection molding and dipping processes to facilitate transition to mass production and to enhance the durability of the antenna. The simulated and measured reflection coefficient of the antenna show good agreement. Measured antenna gain patterns verify that the manufacturing process employed is capable of producing low loss antenna structures. Lastly, time domain short pulse measurements of the antenna verify that it does not appreciably distort radiated signals in the azimuthal plane.

The Puck Antenna: A Compact Design With Wideband, High-Gain Operation

Abstract: We develop a high-gain antenna with wideband operation and compact size by placing a small dielectric superstrate (puck) in front of the feeding antenna. The antenna performance is a combination of the leaky-wave effect, naturally existing in this type of antennas, and the edge diffraction effect occurring at the puck perimeter. Compared to the typical resonant cavity antenna utilizing a large superstrate, the proposed puck antenna has nearly four times enhanced performance (gain-bandwidth combination) while using a square puck of side slightly smaller than two wavelengths (at the design frequency). Further enhancement is achieved by making the puck circular in shape in order to add the diffracted fields in phase. The study is conducted through full-wave simulations and validated through measurements in the $Ku$ band. The effect of puck misalignment is then discussed as a potential practical issue. Last, the ground plane is optimized for maximum antenna performance and relatively acceptable values of aperture efficiency (up to 51%).

Polymers for 3D Printing and Customized Additive Manufacturing

Abstract: Additive manufacturing (AM) alias 3D printing translates computer-aided design (CAD) virtual 3D models into physical objects. By digital slicing of CAD, 3D scan, or tomography data, AM builds objects layer by layer without the need for molds or machining. AM enables decentralized fabrication of customized objects on demand by exploiting digital information storage and retrieval via the Internet. The ongoing transition from rapid prototyping to rapid manufacturing prompts new challenges for mechanical engineers and materials scientists alike. Because polymers are by far the most utilized class of materials for AM, this Review focuses on polymer processing and the development of polymers and advanced polymer systems specifically for AM. AM techniques covered include vat photopolymerization (stereolithography), powder bed fusion (SLS), material and binder jetting (inkjet and aerosol 3D printing), sheet lamination (LOM), extrusion (FDM, 3D dispensing, 3D fiber deposition, and 3D plotting), and 3D bioprinting....

Gain enhancement methods for printed circuit antennas

Abstract: Resonance conditions for a substrate-superstrate printed antenna geometry which allow for large antenna gain are presented. Asymptotic formulas for gain, beamwidth, and bandwidth are given, and the bandwidth limitation of the method is discussed. The method is extended to produce narrow patterns about the horizon, and directive patterns at two different angles.

Transparent paper: fabrications, properties, and device applications

Abstract: Although paper electronics is a compelling concept, the large surface roughness and opaqueness of most paper substrates has hindered its development from a dormant idea to a thriving technology. A recent demonstration of transparent paper with nanoscale surface roughness has revived an interest in using renewable cellulose substrates for electronics and optoelectronics. In this short review, we will first summarize the recent progress of transparent paper electronics through structure engineering. We will also discuss the properties and functionalization of transparent paper, such as surface roughness, printability, thermal stability, etc. Finally, we will summarize the recent achievements on proof-of-concepts of transparent paper, which pave the way for next-generation green electronics fabricated with roll-to-roll printing methods. Advantages of transparent paper over traditional flexible plastic substrates and its challenges will also be discussed.

A New Frontier of Printed Electronics: Flexible Hybrid Electronics.

Abstract: The performance and integration density of silicon integrated circuits (ICs) have progressed at an unprecedented pace in the past 60 years. While silicon ICs thrive at low-power high-performance computing, creating flexible and large-area electronics using silicon remains a challenge. On the other hand, flexible and printed electronics use intrinsically flexible materials and printing techniques to manufacture compliant and large-area electronics. Nonetheless, flexible electronics are not as efficient as silicon ICs for computation and signal communication. Flexible hybrid electronics (FHE) leverages the strengths of these two dissimilar technologies. It uses flexible and printed electronics where flexibility and scalability are required, i.e., for sensing and actuating, and silicon ICs for computation and communication purposes. Combining flexible electronics and silicon ICs yields a very powerful and versatile technology with a vast range of applications. Here, the fundamental building blocks of an FHE system, printed sensors and circuits, thinned silicon ICs, printed antennas, printed energy harvesting and storage modules, and printed displays, are discussed. Emerging application areas of FHE in wearable health, structural health, industrial, environmental, and agricultural sensing are reviewed. Overall, the recent progress, fabrication, application, and challenges, and an outlook, related to FHE are presented.

Inorganic nanomaterials for printed electronics: a review

Abstract: Owing to their capability of bypassing conventional high-priced and inflexible silicon based electronics to manufacture a variety of devices on flexible substrates by using large-scale and high-volume printing techniques, printed electronics (PE) have attracted increasing attention in the field of manufacturing industry for electronic devices This simple and cost-effective approach could enhance current methods of constructing a patterned surface for nanomaterials and offer opportunities for developing fully-printed functional devices, especially offering the possibility of ubiquitous low-cost and flexible devices This review presents a summary of work to date on the inorganic nanomaterials involved in PE applications, focused on the utilization of inorganic nanomaterials-based inks in the successful preparation of printed conductive patterns, electrodes, sensors, thin film transistors (TFTs) and other micro-/nanoscale devices The printing techniques, sintering methods and printability of functional inks with their associated challenges are discussed, and we look forward so you can glimpse the future of PE applications