The vision of next generation 5G wireless communications lies in providing very high data rates (typically of Gbps order), extremely low latency, manifold increase in base station capacity, and significant improvement in users’ perceived quality of service (QoS), compared to current 4G LTE networks. Ever increasing proliferation of smart devices, introduction of new emerging multimedia applications, together with an exponential rise in wireless data (multimedia) demand and usage is already creating a significant burden on existing cellular networks. 5G wireless systems, with improved data rates, capacity, latency, and QoS are expected to be the panacea of most of the current cellular networks’ problems. In this survey, we make an exhaustive review of wireless evolution toward 5G networks. We first discuss the new architectural changes associated with the radio access network (RAN) design, including air interfaces, smart antennas, cloud and heterogeneous RAN. Subsequently, we make an in-depth survey of underlying novel mm-wave physical layer technologies, encompassing new channel model estimation, directional antenna design, beamforming algorithms, and massive MIMO technologies. Next, the details of MAC layer protocols and multiplexing schemes needed to efficiently support this new physical layer are discussed. We also look into the killer applications, considered as the major driving force behind 5G. In order to understand the improved user experience, we provide highlights of new QoS, QoE, and SON features associated with the 5G evolution. For alleviating the increased network energy consumption and operating expenditure, we make a detail review on energy awareness and cost efficiency. As understanding the current status of 5G implementation is important for its eventual commercialization, we also discuss relevant field trials, drive tests, and simulation experiments. Finally, we point out major existing research issues and identify possible future research directions.

Next Generation 5G Wireless Networks: A Comprehensive Survey

Substrate-integrated waveguide (SIW) technology represents an emerging and very promising candidate for the development of circuits and components operating in the microwave and millimetre-wave region. SIW structures are generally fabricated by using two rows of conducting cylinders or slots embedded in a dielectric substrate that connects two parallel metal plates, and permit the implementation of classical rectangular waveguide components in planar form, along with printed circuitry, active devices and antennas. This study aims to provide an overview of the recent advances in the modelling, design and technological implementation of SIW structures and components.

Review of substrate-integrated waveguide circuits and antennas

With the demanding system requirements for the fifth-generation (5G) wireless communications and the severe spectrum shortage at conventional cellular frequencies, multibeam antenna systems operating in the millimeter-wave frequency bands have attracted a lot of research interest and have been actively investigated. They represent the key antenna technology for supporting a high data transmission rate, an improved signal-to-interference-plus-noise ratio, an increased spectral and energy efficiency, and versatile beam shaping, thereby holding a great promise in serving as the critical infrastructure for enabling beamforming and massive multiple-input multiple-output (MIMO) that boost the 5G. This paper provides an overview of the existing multibeam antenna technologies which include the passive multibeam antennas (MBAs) based on quasi-optical components and beamforming circuits, multibeam phased-array antennas enabled by various phase-shifting methods, and digital MBAs with different system architectures. Specifically, their principles of operation, design, and implementation, as well as a number of illustrative application examples are reviewed. Finally, the suitability of these MBAs for the future 5G massive MIMO wireless systems as well as the associated challenges is discussed.

Multibeam Antenna Technologies for 5G Wireless Communications

A novel slotted substrate integrated waveguide (SIW) leaky-wave antenna is proposed. This antenna works in the TE10 mode of the SIW. Leakage is obtained by introducing a periodic set of transverse slots on the top of the SIW, which interrupt the current flow on the top wall. It is seen that three modes (a leaky mode, a proper waveguide mode, and a surface-wave-like mode) can all propagate on this structure. The wavenumbers of the modes are calculated theoretically and are numerically evaluated by HFSS simulation. The leakage loss, dielectric loss, and conductor loss are also analyzed. A uniform slotted SIW leaky-wave antenna is designed that has good beam scanning from near broadside (though not exactly at broadside) to forward endfire. This type of SIW leaky-wave antenna has a wide impedance bandwidth and a narrow beam that scans with frequency. Measured results are consistent with the simulation and the theoretical analysis.

Substrate Integrated Waveguide (SIW) Leaky-Wave Antenna With Transverse Slots

A substrate integrated waveguide with square complementary split-ring resonators (CSRRs) etched on the waveguide surface is investigated in this paper. The proposed structures allow the implementation of a forward-wave passband propagating below the characteristic cutoff frequency of the waveguide. By changing the orientations of the CSRRs, which are incorporated in the waveguide surface and can be interpreted in terms of electric dipoles, varied passband characteristics are observed. A detailed explanation for the generation and variations of the passbands has been illuminated. The application of this waveguide and CSRR combination technique to the design of miniaturized waveguide bandpass filters characterized by transmission zeros is then illustrated. Filter design methodology is examined. These proposed filters exhibit high selectivity and compact size due to the employment of the subwavelength resonators and an evanescent-wave transmission. By slightly altering the configuration of the CSRRs, we find that the propagation of the TE10 mode can be suppressed and filters with improved selectivity and stopband rejection can be obtained. To verify the presented concept, three different types of filters are fabricated based on the standard printed circuit board process. The measured results are in good agreement with the simulation.

Substrate Integrated Waveguide Loaded by Complementary Split-Ring Resonators and Its Applications to Miniaturized Waveguide Filters

The utility model relates to a millimeter wave band multi-mode beam shaping network applicable to microwave millimeter wave multibeam antenna-feed systems and intelligent antenna systems. The network has a plane circuit structure; an upper-layer copper clad face (1) and a lower-layer copper clad face (2) are respectively located on both sides of the medium substrate (3); a metalized through hole (4) runs through a medium substrate (3) and is connected with the upper-layer copper clad face (1) and the lower-layer copper clad face (2) to form a multi-mode substrate waveguide (5) and a substrate integrated waveguide phase-shifting network (6); the multi-mode substrate waveguide (5) and the substrate integrated waveguide phase-shifting network (6) are connected directly; the input end (51) is located on one side of the multi-mode substrate integrated waveguide (5), and an inner output port (52) is located on the other side of the multi-mode substrate integrated waveguide (5) and is connected with the inner side of the substrate integrated waveguide phase-shifting network (6); and the outer side of the substrate integrated waveguide phase-shifting network (6) is connected with an external output port (7).

Multiple mode beam forming network for millimeter wave frequency band

The utility model discloses a high-gain low-loss substrate integrated waveguide multiple-beam antenna applicable to microwave millimeter wave beam-shaping network and multiple-beam antenna feed systems. The substrate integrated waveguide multiple-beam antenna achieved by such technical proposal can be applied to microwave millimeter-wave multiple-beam antenna and intelligent antenna technology. The antenna comprises an upper-layer copper surface (1), a lower-layer copper surface (2), a medium substrate (3), metalized through-holes (4), a circle (5) formed by the metalized through-holes, an input port (51), an output port (52), a matching port (53), a substrate integrated waveguide phase-shifting network (6), a radiating antenna array (7), a substrate integrated waveguide slot array antenna (71) and slots (72) on the metal surface.

High gain low loss multi-beam antenna for substrate integrated waveguide

Based on the substrate integrated waveguide technology, multiple antennas are developed at W-band for MIMO application. With the normal PCB process, such multiple antennas possess the advantages of compact structure, low cost, easy manufacture, and easy integration etc. High isolation feature is achieved. The simulated and measured results are in good agreement.

94-GHz substrate integrated waveguide multiple antennas with high isolation characteristic for MIMO application

In this paper, some recent simulation and experiment results of the channel characteristics for in-car high-speed wireless communication are presented.

Simulation and experiment on in-car channel characteristics

P.30 A wideband waveguide slot array antenna element for high-resolution SAR application Xiaole Yu, Daning Ni, Zhengjun Li, Wutu Wang (China Mainland) P.31 Simulation of Monifilar Archimedean conical spiral antennas Chen Chen, Fang Yang, Chenjiang Guo, Jiadong Xu (China Mainland) P.32 A Modified Broadband Transmission Line Model for rectangular Patch Antennas

Zhenqi Kuai

Papers

Multiple mode beam forming network for millimeter wave frequency band

High gain low loss multi-beam antenna for substrate integrated waveguide

94-GHz substrate integrated waveguide multiple antennas with high isolation characteristic for MIMO application

Simulation and experiment on in-car channel characteristics