Multiband Antennas Design Techniques for 5G Networks: Present and Future Research Directions

With the development of wireless communication system has demanded compact wireless devices that allow more space to integrate the other electronics components. Advancement in technology creates challenges in implementing antenna for multiple RF band with a wide range of frequencies. With the advancement of optimization technique we can improve the antenna design as well as provide us the motivation of analyzing the existing studies in order to categorize and synthesize them in a meaningful manner. The objective of this paper contributes in two ways. First, it provides the research and development trends and novel approaches in design of multiband MIMO, smart reconfigurable and defected ground structure (DGS) antenna techniques for wireless system. Secondly, it highlights unique design issue reported in literature. The proposed paper aim is filling the gap in the literature and providing the researcher a useful reference

Recent Advances in Antenna Design for 5G Heterogeneous Networks

The aim of this book is to highlight up to date exploited technologies and approaches in terms of antenna designs and requirements. In this regard, this book targets a broad range of subjects, including the microstrip antenna and the dipole and printed monopole antenna. The varieties of antenna designs, along with several different approaches to improve their overall performance, have given this book a great value, in which makes this book is deemed as a good reference for practicing engineers and under/postgraduate students working in this field. The key technology trends in antenna design as part of the mobile communication evolution have mainly focused on multiband, wideband, and MIMO antennas, and all have been clearly presented, studied and implemented within this book. The forthcoming 5G systems consider a truly mobile multimedia platform that constitutes a converged networking arena that not only includes legacy heterogeneous mobile networks but advanced radio interfaces and the possibility to operate at mm wave frequencies to capitalize on the large swathes of available bandwidth. This provides the impetus for a new breed of antenna design that, in principle, should be multimode in nature, energy efficient, and, above all, able to operate at the mm wave band, placing new design drivers on the antenna design. Thus, this book proposes to investigate advanced 5G antennas for heterogeneous applications that can operate in the range of 5G spectrums and to meet the essential requirements of 5G systems such as low latency, large bandwidth, and high gains and efficiencies

Metasurface-Based Wideband MIMO Antenna for 5G Millimeter-Wave Systems

This paper presents a metasurface based multiple-input multiple-output (MIMO) antenna with a wideband operation for millimeter-wave 5G communication systems. The antenna system consists of four elements placed with a 90 degree shift in order to achieve a compact MIMO system while a 2 x 2 non-uniform metasurface (total four elements) is placed at the back of the MIMO configuration to improve the radiation characteristics of it. The overall size of the MIMO antenna is 24 x 24 mm(2) while the operational bandwidth of the proposed antenna system ranges from 23.5-29.4 GHz. The peak gain achieved by the proposed MIMO antenna is almost 7dB which is further improved up to 10.44 dB by employing a 2 x 2 metasurface. The total efficiency is also observed more than 80% across the operating band. Apart from this, the MIMO performance metrics such as envelope correlation coefficient (ECC), diversity gain (DG), and channel capacity loss (CCL) are analyzed which demonstrate good characteristics. All the simulations of the proposed design are carried out in computer simulation technology (CST) software, and measured results reveal good agreement with the simulated one which make it a potential contender for the upcoming 5G communication systems

Metasurface-based wideband MIMO antenna for 5G millimeter-wave systems

This paper presents a metasurface based multiple-input multiple-output (MIMO) antenna with a wideband operation for millimeter-wave 5G communication systems. The antenna system consists of four elements placed with a 90 degree shift in order to achieve a compact MIMO system while a 2× 2 non-uniform metasurface (total four elements) is placed at the back of the MIMO configuration to improve the radiation characteristics of it. The overall size of the MIMO antenna is 24× 24 mm2 while the operational bandwidth of the proposed antenna system ranges from 23.5-29.4 GHz. The peak gain achieved by the proposed MIMO antenna is almost 7dB which is further improved up to 10.44 dB by employing a 2× 2 metasurface. The total efficiency is also observed more than 80% across the operating band. Apart from this, the MIMO performance metrics such as envelope correlation coefficient (ECC), diversity gain (DG), and channel capacity loss (CCL) are analyzed which demonstrate good characteristics. All the simulations of the proposed design are carried out in computer simulation technology (CST) software, and measured results reveal good agreement with the simulated one which make it a potential contender for the upcoming 5G communication systems.This work was supported in part by the Universidad Carlos III de Madrid and the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant Agreement No 801538, and in part by the the Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER,UE) under Grant RTI2018-095499-B-C31

IEEE Access Special Section: Antenna and Propagation for 5G and Beyond

5G is not just the next evolution of 4G technology; it is a paradigm shift. “5G and beyond” will enable bandwidth in excess of 100s of Mb/s with a latency of less than 1 ms, in addition to providing connectivity to billions of devices. The verticals of 5G and beyond are not limited to smart transportation, industrial IoT, eHealth, smart cities, and entertainment services, transforming the way humanity lives, works, and engages with its environment

Mutual coupling suppression between two closely placed microstrip patches using EM-bandgap metamaterial fractal loading

An approach is proposed to reduce mutual coupling between two closely spaced radiating elements. This is achieved by inserting a fractal isolator between the radiating elements. The fractal isolator is an electromagnetic bandgap structure based on metamaterial. With this technique, the gap between radiators is reduced to ∼0.65λ for the reduction in the mutual coupling of up to 37, 21, 20, and 31 dB in the X-, Ku-, K-, and Ka-bands, respectively. With the proposed technique, the two-element antenna is shown to operate over a wide frequency range, i.e., 8.7–11.7, 11.9–14.6, 15.6–17.1, 22–26, and 29–34.2 GHz. Maximum gain improvement is 71% with no deterioration in the radiation patterns. The antenna’s characteristics were validated through measurement. The proposed technique can be applied retrospectively and is applicable in closely placed patch antennas in arrays found in multiple-input multiple-output and radar systems

Frequency Tunable Filtenna Using Defected Ground Structure Filter in the Sub-6 GHz for Cognitive Radio Applications

In this paper, a new frequency tunable filtering-antenna (so-called filtenna) is inspired by a Defected Ground Structure (DGS) band-pass filter for the fifth generation picocell base stations. It is intended for use in Cognitive Radio (CR) communications within the European Union Sub-6 GHz spectrum, which ranges between 3.4 and 3.8 GHz. Firstly, a Wideband (WB) monopole antenna is proposed where the operational frequencies cover 3.15–4.19 GHz, taking the 10-dB return loss level as a threshold. A band-pass filter of a Semi-Square Semi-Circle shape is integrated into the WB antenna ground to obtain the communicating filtenna. The narrowband frequency tunability is achieved by changing two varactor diode capacitances located in the filter slots. The antenna is prototyped occupying a total space of 60 7 80 7 0.77 mm3, then tested to verify the simulated results. Three operating frequencies 3.4, 3.6, and 3.8 GHz of the filtenna are studied in terms of return loss, realized gain, and radiation patterns which verify that the frequency shift has almost no effect on the antenna performance. The filtenna has a maximum gain of 4.5 dBi in measurements and 3.47 dBi in simulations. The obtained results have proved their efficiency for CR communications

Vaiheensiirtimien integrointi aaltoputkiohjattuun antenniryhmään

In this master’s thesis, phase shifter integration for the future 5G base station antennas is studied using electromagnetic simulations and measurements. The integration is done for two antenna prototypes, which operate at 71–86 GHz band (E-band) and 26–30 GHz band (cm-band), respectively. The base station antenna is a waveguide-fed phased array and the phase shifters are integrated on a PCB, which is installed between the feeding network and a horn antenna array. Two waveguide-to-microstrip transitions are designed and simulated for both frequency bands. The average insertion losses of the transitions are 0.7 dB at E-band, and 0.35 dB at cm-band, confirming suitability for the antenna prototypes. A sensitivity analysis of the main transition parameters suggests that manufacturing precision should be ±30 µm at E-band and ±50 µm at cm-band, respectively. Fixed microstrip line-based true time delay phase shifters are designed for E-band. Their performance is validated by simulations and measurements. The results show that the phase shifters have full 360°phase shift range for the beam-steering demonstration of the prototype antenna. TGP2100 phase shifters from TriQuint are used for cm-band. A test structure is fabricated and measured to characterize the phase shifter but it is damaged during the phase shifter installation. Other test structures are designed and measured to evaluate losses due to wire bonding of the phase shifter to the PCB. The measurement results show the insertion loss from the wire bonding is around 4 dB. Also, a phase shifter test structure made by Nokia Bell Labs is simulated and measured. The results show that the used phase shifter simulation model does not predict the phase shifter performance correctly when the RF-grounding is defected e.g. due to unsuitable glue or solder. The simulations indicate that the main source of antenna prototype transmission losses are the phase shifters. Still, the phase shifters are suitable for the beam-steering demonstration. Future work includes fabricating the final antenna prototype for the cm-band and its measurements.Tässä diplomityössä on tutkittu vaiheensiirtimien integrointia tulevaisuuden 5G tukiasema-antenneihin käyttäen apuna sähkömagneettisia simulaatioita ja mittauksia. Integrointi on toteutettu kahdelle antenniprototyypille, jotka toimivat 71–86 GHz (E-kaista) ja 26–30 GHz (cm-kaista) taajuuksilla. Tukiasema-antenni on aaltoputkilla syötetty, vaiheohjattu antenniryhmä ja vaiheensiirtimet integroidaan piirilevylle, joka asennetaan syöttöverkon ja torviantenniryhmän väliin. Kaksi aaltoputki-mikroliuska-siirtymää on suunniteltu ja simuloitu molemmille taajuuskaistoille. Simulaatiotulokset osoittavat, että siirtymillä on pienet keskimääräiset väliinkytkemisvaimennukset: 0,7 dB E-kaistalla ja 0,35 dB cm-kaistalla, joten ne sopivat käytettäväksi antenniprototyypeissä. Siirtymän tärkeimmistä mitoista tehty herkkyysanalyysi osoittaa että ±30 µm valmistustarkkuus on riittävä E-kaistalle ja ±50 µm valmistustarkkuus cm-kaistalle. Kiinteät mikroliuskapohjaiset vaiheensiirtimet on suunniteltu E-kaistalle. Niiden toiminnallisuus on varmistettu simuloinneilla ja mittauksilla. Tulokset osoittavat, että vaiheensiirtimillä voidaan toteuttaa 360°:een vaiheensiirto ja ne sopivat käytettäväksi prototyyppiantennin vaiheistamiseen. TriQuintin valmistamia TGP2100-vaiheensiirtimiä käytetään cm-kaistalla. Testirakenne valmistettiin vaiheensiirtimen karakterisointia varten, mutta testialustalle asennetun vaiheensiirtimen havaittiin olevan vahingoittunut. Muita testirakenteita on suunniteltu ja mitattu vaiheensiirtimen lankabondauksesta johtuvien häviöiden selvittämiseksi: lankabondauksesta aiheutuu noin 4 dB:n häviöt. Lisäksi Nokia Bell Labsin valmistama testirakenne on simuloitu ja mitattu. Tuloksista nähdään, että vaiheensiirtimen simulaatiomalli ei toimi oletetulla tavalla, jos vaiheensiirtimen RF-maadoitus on viallinen. Tämä voi johtua esimerkiksi sopimattomasta liimasta tai juotteesta. Simulaatiot osoittavat, että vaiheensiirtimet ovat antenniprototyyppien pääasiallinen siirtohäviölähde, mutta ne sopivat antennin vaiheistamisen esittelyyn. Tutkimusta aiotaan jatkaa valmistamalla antenniprototyyppi cm-kaistalle ja mittaamalla sen toiminta

Towards an Advanced Automotive Radar Front-end Based on Gap Waveguide Technology

This thesis presents the early works on dual circularly polarized array antenna based on gap waveguide, also microstrip-to-waveguide transitions for integration of automotive radar front-end. Being the most widely used radar antenna, PCB antenna suffers from dielectric loss and design flexibility. Next generation automotive radars demand sophisticated antenna systems with high efficiency, which makes waveguide antenna become a better candidate. Over the last few years, gap waveguide has shown advantages for implementation of complicated antenna systems. Ridge gap waveguides have been widely used in passive gap waveguide components design including slot arrays. In this regard, two transitions between ridge gap waveguides and microstrip lines are presented for the integration with gap waveguide antennas. The transitions are verified in both passive and active configuration. Another work on packaging techniques is presented for integration with inverted microstrip gap waveguide antennas.Systems utilizing individual linear polarization (LP) that lack polarimetric capabilities are not capable of measuring the full scattering matrix, thus losing information about the scenery. To develop a more advanced radar system with better detectability, dual circularly polarized gap waveguide slot arrays for polarimetric radar sensing are investigated. An 8 78 planar array using double grooved circular waveguide polarizer is presented. The polarizers are compact in size and have excellent polarization properties. Multi-layer design of the array antenna benefits from the gap waveguide technology and features better performance. The works presented in this thesis laid the foundation of future works regarding integration of the radar front end. More works on prototyping radar systems using gap waveguide technology will be presented in future publications

Miniaturized Resonator and Bandpass Filter for Silicon-Based Monolithic Microwave and Millimeter-Wave Integrated Circuits

© 2018 IEEE. © 2018 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission.This paper introduces a unique approach for the implementation of a miniaturized on-chip resonator and its application for the first-order bandpass filter (BPF) design. This approach utilizes a combination of a broadside-coupling technique and a split-ring structure. To fully understand the principle behind it, simplified LC equivalent-circuit models are provided. By analyzing these models, guidelines for implementation of an ultra-compact resonator and a BPF are given. To further demonstrate the feasibility of using this approach in practice, both the implemented resonator and the filter are fabricated in a standard 0.13-μm (Bi)-CMOS technology. The measured results show that the resonator can generate a resonance at 66.75 GHz, while the BPF has a center frequency at 40 GHz and an insertion loss of 1.7 dB. The chip size of both the resonator and the BPF, excluding the pads, is only 0.012mm 2 (0.08 × 0.144 mm 2).Peer reviewe