Study of mm-wave Fixed Beam and Frequency Beam-Scanning Antenna Arrays

Millimeter-wave frequencies are anticipated to be widely adapted for future wireless communication systems to resolve the demand of high data-rate and capacity issues. The millimeter-wave frequency range offers wide spectrum and a shift for most newly developing technologies as the microwave and lower frequency bands are becoming overcrowded and congested. These high frequency bands offer short wavelengths which has enabled the researchers to design and implement compact and adaptable antenna solutions. This research focuses on the implementation, transformation and modification of antenna structures used in lower frequency bands to millimeter-wave applications with high gain and multi-band and wideband performances. The first part of the thesis presents a microstrip patch array antenna with high gain in the upper 26 GHz range for 5G applications. The tolerance of the antenna, on widely used Rogers RT/duroid 5880 substrate, is observed with the edge-fed structure when curved in both concave and convex directions. In the second part of the thesis, 20 rectangular loops are arranged in a quasi-rhombic shaped planar microstrip grid array antenna configuration with dual-band millimeter-wave performance. A comparison with equal sized microstrip patch array is also presented to analyse the performance. The antenna operates in the upper 26 GHz band and has two frequency bands in close proximity. The third part of the thesis discusses the transition from wire Bruce array antenna to planar technology. Having been around for nearly a century and despite the simplicity of structure, the research community has not extended the concept of Bruce array antenna for further research. The proposed planar Bruce array antenna operates in three frequency v bands with optimization focus on 28.0 GHz band that has a directive fan-beam radiation pattern at broadside whereas the other two frequency ranges, above 30 GHz, have dual-beam radiation patterns which provide radiation diversity in narrow passages. The final part of the thesis deals with the transformation and modification of wire Bruce array antenna geometry to edge-fed printed leaky-wave antennas for millimeter-wave frequency scanning applications. In the first approach, the lengths of the unit-cell are optimised, without any additional circuitry, to enable two scanning ranges and mitigate the Open-Stopband, at broadside, for seamless scanning in the first range. A Klopfen-stein tapered divider is then deployed to make a linear array of the proposed antenna to achieve high gain. In the second approach, the horizontal and vertical lengths of the meandered unit-cell are replaced with semi-circular and novel bowtie elements, respectively, to obtain wide scanning range. The numerical results and optimizations have been performed using CST Micro-wave Studio where the effects of metallization and dielectric losses are properly consid-ered. The prototypes of the proposed antennas have been fabricated and experimentally validated

Design of microstrip patch antenna to deploy unmanned aerial vehicle as UE in 5G wireless network

The use of unmanned aerial vehicle (UAV) has been increasing rapidly in the civilian and military applications, because of UAV's high-performance communication with ground clients, especially for its intrinsic properties such as adaptive altitude, mobility, and flexibility. UAV deployment can be monitored and controlled through 5G wireless network as user equipment (UE) along with other devices. A highly directive microstrip patch antenna (MPA) could establish long-distance communication by overcoming air attenuation and reduce co-channel interference in the limited region if UAV uses a specifically dedicated band, which might enhance spatially reuse of the spectrum. Also, MPA is highly recommended for UAV because of its low weight, low cost, compact size, and flat shape. In this paper, we have designed a highly directive single-band 2×2 and 4×4 antenna array for 5.8 GHz and 28 GHz frequency respectively for UAV application in a focus to deploy UAV through 5G wireless network. Here, The Roger RT5880 (lossy) material utilize as a substrate due to its lower dielectric constant which achieves higher directivity and good mechanical stability. Inset feed technique used to feed antenna for lowering input impedance which provides higher antenna efficiency. The results show a wider bandwidth of 702 MHz and 1.596 GHz for 5.8 GHz and 28 GHz antenna array correspondingly with a compact size

A 37 GHz Millimeter-Wave Antenna Array for 5G Communication Terminals

This work presents, design and specific absorption rate (SAR) analysis of a 37 GHz antenna, for 5th Generation (5G) applications. The proposed antenna comprises of 4-elements of rectangular patch and an even distribution. The radiating element is composed of copper material supported by Rogers RT5880 substrate of thickness, 0.254 mm, dielectric constant (εr), 2.2, and loss tangent, 0.0009. The 4-elements array antenna is compact in size with a dimension of 8 mm × 20 mm in length and width. The radiating patch is excited with a 50 ohms connector i.e., K-type. The antenna resonates in the frequency band of 37 GHz, that covers the 5G applications. The antenna behavior is studied both in free space and in the proximity of the human body. Three models of the human body, i.e., belly, hand, and head (contain skin, fat, muscles, and bone) are considered for on-body simulations. At resonant frequency, the antenna gives a boresight gain of 11.6 dB. The antenna radiates efficiently with a radiated efficiency of more than 90%. Also, it is observed that the antenna detunes to the lowest in the proximity of the human body, but still a good impedance matching is achieved considering the −10 dB criteria. Moreover, SAR is also being presented. The safe limit of 2 W/kg for any 10 g of biological tissue, specified by the European International Electro Technical Commission (IEC) has been considered. The calculated values of SAR for human body models, i.e., belly, hand and head are 1.82, 1.81 and 1.09 W/kg, respectively. The SAR values are less than the international recommendations for the three models. Furthermore, the simulated and measured results of the antenna are in close agreement, which makes it, a potential candidate for the fifth-generation smart phones and other handheld devices

Designing MIMO Omnidirectional Millimeter-Wave MetamaterialAntenna for 5G Communications

A highly efficient, low profile, wideband metamaterial antenna is presented for mm-wave 5G communications. The designed metamaterial resonator structure works as a radiator and operates in the FCC auctioned 28 GHz frequency spectrum (27.5 - 28.350 GHz). The proposed antenna is fabricated on a 10.3mm x 10.3mm and .0787 mm thick Rogers RT5880/Duroid substrate and probe feed is used as the feeding mechanism. The effect of different design parameters on the performance of the antenna is examined and then optimized for the best possible performance. The designed antenna shows wideband characteristics with an impedance bandwidth of 2.22 GHz (27.49 – 29.71 GHz) measured at -10 dB. The structure is simulated in CST microwave studio and then fabricated. The measured radiation pattern is omnidirectional with a peak gain of 3.74 dB and a radiation efficiency of 95%. The antenna has a total efficiency of 92%. Furthermore, the diversity performance of the MIMO antenna is investigated which shows a maximum coupling of -13.5 dB measured at 28 GHz frequency band

Antenna Design for 5G and Beyond

With the rapid evolution of the wireless communications, fifth-generation (5G) communication has received much attention from both academia and industry, with many reported efforts and research outputs and significant improvements in different aspects, such as data rate speed and resolution, mobility, latency, etc. In some countries, the commercialization of 5G communication has already started as well as initial research of beyond technologies such as 6G.MIMO technology with multiple antennas is a promising technology to obtain the requirements of 5G/6G communications. It can significantly enhance the system capacity and resist multipath fading, and has become a hot spot in the field of wireless communications. This technology is a key component and probably the most established to truly reach the promised transfer data rates of future communication systems. In MIMO systems, multiple antennas are deployed at both the transmitter and receiver sides. The greater number of antennas can make the system more resistant to intentional jamming and interference. Massive MIMO with an especially high number of antennas can reduce energy consumption by targeting signals to individual users utilizing beamforming.Apart from sub-6 GHz frequency bands, 5G/6G devices are also expected to cover millimeter-wave (mmWave) and terahertz (THz) spectra. However, moving to higher bands will bring new challenges and will certainly require careful consideration of the antenna design for smart devices. Compact antennas arranged as conformal, planar, and linear arrays can be employed at different portions of base stations and user equipment to form phased arrays with high gain and directional radiation beams. The objective of this Special Issue is to cover all aspects of antenna designs used in existing or future wireless communication systems. The aim is to highlight recent advances, current trends, and possible future developments of 5G/6G antennas

MM-Wave phased array Quasi-Yagi antenna for the upcoming 5G cellular communications

This article belongs to the Special Issue Millimeter-wave and Terahertz Applications of Metamaterials.The focus of this manuscript was to propose a new phased array antenna design for the fifth generation (5G) mobile platforms. Eight elements of compact Quasi-Yagi antennas were placed on the top portion of smartphone printed circuits board (PCB) to form a beam-steerable phased array design. The −10 dB impedance-bandwidth of proposed 5G smartphone antenna spans from 25 GHz to 27 GHz providing 2 GHz bandwidth with less than −16 dB mutual coupling function. A coax-to-microstripline with a truncated crown of vias around the coaxial cable was used as a feeding mechanism for each radiation element. An Arlon Ad 350 substance with properties of ε = 3.5, δ = 0.003, and h = 0.8 mm was chosen as the antenna substrate. The proposed phased array antenna provides wide-angle scanning of 0°~75° with more than 10 dB realized gain levels. For the scanning angle of 0°~60°, the antenna array provides more than 90% (−0.5 dB) radiation and total efficiencies. In addition, the specific absorption rate (SAR) function and radiation performance of the design in the presence of the user-hand/user-hand have been studied. The results validate the feasibility of the proposed design for use in the 5G handheld devices. Furthermore, using the presented Quasi-Yagi elements, the radiation properties of 2 × 2, 4 × 4, and 8 × 8 planar arrays were studied and more than 8.3, 13.5, and 19.3 dBi directivities have been achieved for the designed planar arrays. The results show that the designed arrays (linear & planar) satisfy the general requirements for use in 5G platforms.This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424

Antennas and Propagation Aspects for Emerging Wireless Communication Technologies

The increasing demand for high data rate applications and the delivery of zero-latency multimedia content drives technological evolutions towards the design and implementation of next-generation broadband wireless networks. In this context, various novel technologies have been introduced, such as millimeter wave (mmWave) transmission, massive multiple input multiple output (MIMO) systems, and non-orthogonal multiple access (NOMA) schemes in order to support the vision of fifth generation (5G) wireless cellular networks. The introduction of these technologies, however, is inextricably connected with a holistic redesign of the current transceiver structures, as well as the network architecture reconfiguration. To this end, ultra-dense network deployment along with distributed massive MIMO technologies and intermediate relay nodes have been proposed, among others, in order to ensure an improved quality of services to all mobile users. In the same framework, the design and evaluation of novel antenna configurations able to support wideband applications is of utmost importance for 5G context support. Furthermore, in order to design reliable 5G systems, the channel characterization in these frequencies and in the complex propagation environments cannot be ignored because it plays a significant role. In this Special Issue, fourteen papers are published, covering various aspects of novel antenna designs for broadband applications, propagation models at mmWave bands, the deployment of NOMA techniques, radio network planning for 5G networks, and multi-beam antenna technologies for 5G wireless communications

Design of a Novel Efficient High-Gain Ultra-Wide-Band Slotted H-Shaped Printed 2×1 Array Antenna for Millimeter-Wave Applications with Improvement of Bandwidth and Gain via the Feed Line and Elliptical Edges

This paper describes design procedure of a high-performance miniaturized antenna with an array configuration, which contributes to enhancing the communication system’s performance. The basic antenna features a compact size (6 x 6) mm2, and its single element is an H-shaped slotted patch printed on the top side of a Rogers RT5880 substrate, with a relative permittivity and thickness of 2.2 and 0.3 mm, respectively. The edge-to-edge distance of the 2 × 1 array antenna is 9 x 14 mm2, and the isolation between its radiation elements is 4.5 mm. To increase the capabilities of the antenna in terms of gain and bandwidth, we proceeded to use the 2 × 1 array configuration and then optimized the model via either the width of the feed line or the elliptical edges of the patch. The miniaturized array antenna achieved a peak gain of 12.56 dB, a directivity of 13.11 dBi, and a return loss of -47.52 dB at a resonance frequency of 91.5 GHz, with a radiation efficiency of more than 91% over an operating bandwidth of 15.83 GHz, ranging from 79.7 GHz to 95.6 GHz. The design and simulation results of the proposed antenna were obtained using the CST Studio software

Designing antennas and RF components for upper millimeter frequencies using advanced substrate technology

Abstract. When shifting towards high frequency range, integration in the RF-front end becomes crucial. The ongoing planning of 6G communications systems causes a need to explore the possibilities beyond current 5G systems. To address the compactness and smaller sizes of the RF circuit components, the Integrated Passive Devices (IPD) multilayer technology provides us one solution to this problem. There are options already being tested in terms of implementing on-chip components, especially Antenna-in-Package (AiP) designs with a variety of different substrates. Among these technologies, Low Temperature Co-Fired Ceramic (LTCC) can be seen as a choice offering the freedom of multiple metal layers. IPD can be used for providing AiP solutions, as well as passive components such as baluns, filters, and power dividers. The main target of this thesis is to explore the possibilities and limitations for high frequency designs offered by IPD technology developed by (VTT) Technical Research Centre of Finland. The technology has already been tested at 20 GHz, but the focus was to reach the D-band (110–170 GHz) frequency range and subsequently up to even G-band (220–330 GHz). The technology utilizes 3 metal layers and a high resistivity silicon substrate (a lossy material). Starting off with simple transmission line structures (microstrip lines, strip lines and coplanar waveguides), the designs up to 330 GHz, provided information on the possibilities offered by this technology. After that, different AiP options were simulated with frequencies ranging from D- band to G- band. In addition to single elements, also antenna arrays were studied. Additionally, bandpass filters were designed. The dielectric thickness and the width and thickness of 3 the metal layers play a pivotal role in defining the performance of all the RF components designed using this technology. Furthermore, the size and pitch of the RF probe pads used to excite the structures show an impact on the overall behavior of the transmission lines.Antennien ja RF-komponenttien suunnittelu ylemmille millimetritaajuuksille edistynyttä substraattitekniikkaa käyttäen. Tiivistelmä. Siirryttäessä korkeammille taajuuskaistoille RF-etupään integrointi on entistä tärkeämpää. Käynnissä oleva kuudennen sukupolven (6G) viestintäjärjestelmien suunnittelu edellyttää nykyisiä 5G-järjestelmiä edistyksellisempien teknologisten mahdollisuuksien tarkastelua. Entistä pienempien RF-piirikomponenttien toteuttaminen vaatii uusia teknisiä ratkaisuja, ja yksi mahdollisuus komponenttien pienentämiseen on käyttää integroituihin passiivirakenteisiin (Integrated Passive Devices, IPD) pohjautuvaa monikerrosteknologiaa. Eri vaihtoehtoja on jo testattu sirulle sijoitettavien komponenttien toteuttamiseen eri substraattimateriaaleilla, etenkin paketoitujen antenniratkaisujen (Antenna-in-Package, AiP) suunnittelemiseksi. Eräs vaihtoehto IPD:lle on matalan lämpötilan yhteissintrattava keraamiteknologia (Low Temperature Co-Fired Ceramic, LTCC), joka mahdollistaa useamman metallikerroksen hyödyntämisen suunniteltaessa AiP-rakenteita sekä muita passiivikomponentteja (kuten symmetrointimuuntajia, suodattimia sekä tehonjakajia). Tämän opinnäytetyön päätavoitteena on tarkastella Valtion teknillisen tutkimuskeskuksen (VTT:n) kehittämän IPD-teknologian mahdollisuuksia ja rajoitteita korkean taajuuden rakenteiden suunnitteluun. IPD-teknologiaa on tähän mennessä testattu 20 GHz:n taajuudelle asti, mutta tässä työssä tarkoituksena on tutkia teknologiaa 110–170 GHz:n taajuuksille (D-kaista) sekä myöhemmin aina 220–330 GHz:iin saakka (G-kaista). Teknologia hyödyntää kolmea metallikerrosta sekä häviöllistä korkean ominaisvastuksen piisubstraattia. Yksinkertaisten siirtojohtorakenteiden (mikroliuskajohto, liuskajohto, koplanaarijohto) suunnittelu aina 330 GHz:n taajuudelle asti antoi tietoa teknologian mahdollisuuksista, minkä jälkeen erilaisia AiP-rakenteita simuloitiin D- ja G-kaistoilla. Yksittäisten antennielementtien ohella tarkasteltiin antenniryhmiä. Työssä suunniteltiin myös kaistanpäästösuodattimia. Käytettävissä olevien metalli- ja substraattikerrosten paksuudella sekä niiden mahdollistamilla liuskanleveyksillä on keskeinen rooli IPD-teknologialla suunniteltujen komponenttien suorituskyvyn kannalta. Lisäksi RF-mittapäiden kontaktikohtien koko ja välimatka vaikuttavat siirtojohtojen ominaisuuksiin

A Compact Elliptical Microstrip Patch Antenna for Future 5G Mobile Wireless Communication

International audienceIn this paper an elliptical inset fed microstrip patch antenna is proposed for future fifth generation (5G) mobile communications. The antenna is mounted on a compact Fr-4 substrate having dimensions 5 X 5 X 1.6 mm 3 with relative permittivity (ε r) 4.4.The antenna is simulated in the HFSS software and the simulated results shows that it is operating at 28 GHz for reflection coefficient (S 11) below-10dB and has relatively stable radiation pattern