Design, Modelling, and Characterisation of Millimetre-Wave Antennas for 5G Wireless Applications

PhDFuture 5G systems and beyond are expected to implement compact and versatile antennas in highly densifi ed millimetre-wave (MMW) wireless networks. This research emphasises on the realisation of 5G antennas provided with wide bandwidth, high gain, adaptable performance, preferably conformal implementation, and feasible bulk fabrication. Ka{band (26.5{40 GHz) is selected based on recent 5G standardisation, and novel antenna geometries are developed in this work on both rigid and flexible substrates by implementing advanced techniques of frequency reconfi guration, multiple-input-multiple- output (MIMO) assembly, as well as wideband and multiband antennas and arrays. Nove lMMW wideband antennas are presented for 5G and spatial diversity at the antenna front-ends is substantially improved by deploying wideband antennas in a MIMO topology for simultaneous multiple-channel communication. However, wideband operation is often associated with efficiency degradation, which demands a more versatile approach that allows the adaptable antenna to select the operating frequency. In this research, high performance recon figurable antennas are designed for frequency selection over Ka- {band. Also, an efficient and conformal antenna front-end solution is developed, which integrates both frequency recon guration and MIMO technology. Gain of the antenna is critically important for 5G systems to mitigate high propagation losses. Antenna design with both high gain and bandwidth is challenging as wideband antennas are traditionally gain-limited, while antenna arrays deliver high gain over a narrow bandwidth. An Enhanced Franklin array model is proposed in this thesis, which aggregates multiband response with high gain performance. Furthermore, novel flexible monopole antenna and array con gurations are realised to attain high gain profi le over the complete Ka{band. These proposed 5G antennas are anticipated as potential contribution in the progress towards the realisation of future wireless networks.EECS Fees Waiver Award and National University of Sciences and Technolog

Millimeter-wave liquid crystal polymer based conformal antenna array for 5G applications

This letter presents the design, fabrication, and performance evaluation of a flexible millimeter-wave (mm-wave) antenna array for the fifth generation (5G) wireless networks operating at Ka-band (26.5-40 GHz). The single element antenna is comprised of a coplanar-waveguide-fed rectangular patch tapered at its sides with two vertically oriented slots. The ground is designed with L-shaped stubs to converge the dispersed radiation pattern for improving the directivity and gain. The antenna fabrication is accomplished by two advanced methods of laser-milling and inkjet printing on a thin film of flexible liquid crystal polymer. A novel and time-efficient method for postprinting sintering is also proposed in this letter. The design is extended in a two-element array for the gain enhancement. Measurements have validated that the proposed antenna array exhibits a bandwidth of 26-40 GHz with a peak gain of 11.35 dBi at 35 GHz, and consistent high gain profile of above 9 dBi in the complete Ka-band. These features recommend the proposed antenna array as an efficient solution for integration in future flexible 5G front ends and mm-wave wearable devices

A Millimetre-Wave Two-Dimensional 64-Element Array for Large-Scale 5G Antenna Subsystems

This paper presents the comprehensive design and evaluation of a novel large-scale millimetre-wave (mm-wave) two-dimensional (2-D) 64-element antenna array, for operation in the 28-GHz frequency band. The primary objective of this work is to study the feasibility of designing a high-performance array based on liquid-crystal polymer (LCP) substrate for the deployment in the fifth generation (5G) wireless communication networks and infrastructures. The planar 5G array has presented an impedance bandwidth of 400-MHz, with a peak gain of 23.2 dBi at 27.7-GHz. Moreover, the operation of the mm-wave antenna array has been analysed and validated through a set of high-resolution full-wave electromagnetic (EM) simulations, conducted based on the time-domain finite integration technique (FIT). The proposed 28-GHz 2-D antenna array is a high-performance subsystem in order to be potentially employed in the next-generation 5G communications

Smart nanotextiles for communication

Together with wireless technology, advances in nanotechnology and rapid and scalable synthesis of nanomaterials including the 2D graphene has transformed the realms of biomedical sciences. Recent research in the areas of drug delivery, cancer therapy, bio-sensing and bio-imaging have exploited the unique structural and physiological features of graphene and its different forms. Along with the Graphene, several other nanomaterials including carbon nanotubes (CNTs), make excellent candidates for applications associated with loading of drugs, cellular imaging, sensing other molecules and in-vivo cancer studies due to their biocompatibility and stability. Assimilating from the fundamentals of electromagnetic, wireless communication, medical and material science, a novel concept of nanonetworks was first introduced in 2008, which stems from the concept that a collection of nanodevices have the potential to harness the innate communication capabilities of the human body, thereby allowing them to cooperate and share information. It is anticipated that the advanced healthcare diagnosis can be realised if an efficient communication mechanism and data transfer are established between these nanodevices. The human body is a good example of a naturally existing communication network. For instance, the nervous system is composed of nerve cells, i.e. neurons that communicate the external stimulus to the brain and enable the communication between different systems by conveying information with a molecular impulse signal known as a spike. The human body needs communication amongst different cells to survive, the proposed intra- and inter-body nanonetworks ensure their stability without mechanically (or physically) disturbing the harmony of the in-built molecular structure of the body. Moreover, in several cases, the medicine technology fails to understand the root cause of the problem but once we have a monitoring network established in our body, we can extract various unknowns and treat them effectively. The vision of nanoscale networking attempts to achieve the functionality and performance of the internet with the exception that node size is measured in nanometres and channels are physically separated by up to hundreds or thousands of nanometres. In addition, nodes are assumed to be mobile and rapidly deployable. Nodes (or nanodevices) are expected to be either self-powered or spread in and around the specific location. In a visionary sense, an ultimate application of nanoscale networking would be an automated process, where the nano-nodes are in motion communicating in a complex dynamic environment of living organisms monitoring diseased or sensitive parts of the body