Antenna Fabrication using 3D printing techniques

This thesis focuses to explore the use of additive manufacturing (AM) techniques to fabricate various radio frequency (RF) devices. 3D printing, a term used for AM has evolved to the point where it is being introduced into various industries, one of these, discussed in this thesis is the fabrication of antennas for the aim to reduce manufacturing costs and time. The aim is to investigate the performance and reliability of a modified low-cost 3D printer to print plastic and metal simultaneously. Accordingly, this thesis will explore the use of two specific AM technologies employed in the fabrication of several types of antennas and surfaces: i.e. the Fused Deposition Modelling (FDM) method and a pneumatic micro dispensing technique for the conductive ink. The variety of antenna and surfaces that will be fabricated using this technique are a collection of patch antennas, dipole antenna and frequency selective surfaces. In addition, this thesis will address the design, fabrication and testing of the stated antennas covering a range of frequencies and their applications. Nonetheless, it is worth mentioning that this paper is not solely limited to the analysis of the two previously mentioned methods but also other addictive manufacturing technologies will be used and discussed in this project to reach a better understanding of the antennas fabrication process. In conclusion, the thesis aims to demonstrate the efficient performance and successful integration of economical 3D printing methods to design and produce antennas, which are one of the most important gateways to communication

3D Printing of Conformal Antennas for Diversity Wrist Worn Applications

This paper presents for the first time the application of 3D printing techniques for the development of conformal antennas for diversity wrist worn wireless communications. Three processes are described with the common challenge of depositing the metallic layers of the antennas on a bracelet fabricated using fuse filament fabrication (FFF). The first is a multistep process which combines adding a layer to smooth the surface of the band, aerosol jetting the metallic tracks, flash curing and then electroplating. The second combines painting the metallic layers by hand and then electroplating. The last process uses a single machine to fabricate both the bracelet and then the metallic layers by means of a direct write system with silver conductive ink. The wrist worn antennas are presented and its performances on the human wrist are discussed. All antennas cover 2.4 GHz and 5.5 GHz used for WLAN communication with the reflection coefficients less than ?10 dB. The diversity wrist worn antennas system is developed for the final two processes. Three WLAN antennas are fabricated at different positions and shape angles within the bracelet. In terms of communications systems, the advantage of this configuration is that it can increase coverage. The radiation patterns of the antenna are nearly omnidirectional in free space and directional on the human wrist. When the patterns of the three antennas are combined together, the coverage for the communication system improves. Simulation results of all antenna designs and studies using the finite integration technique (FIT) agree well with experimental measurement results. The main motivation of this work is to investigate alternative additive manufacturing methods for the development of conformal diversity antennas on customized 3D printed parts

3D Printed Fingernail Antennas for 5G Applications

3D printing of antennas on removable fingernail for on-body communications at microwave and millimetre waves is proposed. Aerosol Jet technology, a fine-feature material deposition solution, has been used to directly print microstrip patch antennas on an acrylonitrile butadiene styrene (ABS) removable finger nail substrate. Two antennas have been printed and assessed, one operating at 15 GHz and the other at 28 GHz. Nanoparticle conductive silver ink has been employed to create the microstrip patch antennas and corresponding transmission line using an Optomec machine. The inks are then cured using a PulseForge machine. A further copper layer is added to the millimeter wave antenna via an electroplating process. The antennas have been simulated and measured off-the-finger and on-the-finger. Simulated and measured reflection coefficients (S 11 ) and radiation patterns are found to be in good agreement. The proposed on-body antennas can find application in the Internet of Things (IoT) where large amount of sensing data can be shared at the microwave and millimetre wave spectrum of future 5G communications. The removable finger nails could include other electronic devices such as on-body sensors, computational, storage and communication systems