5G Wireless Applications Research Articles

Broadband circularly polarized 2 × 2 MIMO array for midband 5G wireless applications

Abstract The novel compact size orthogonally fed 2 x 2 Multiple Input and Multiple Output (MIMO) array antenna for mid-band Fifth Generation (5G) wireless application is presented. The antenna configuration consists of diamond-shaped patches employed at the top of substrate. The V-shaped common ground slot structure is employed at the bottom of substrate. A broadband circular polarization is achieved by simply combining two circular polarization modes obtained from ground V slot and top patch feed structure. Mainly, the impedance bandwidth (IBW) and gain are enhanced by protruding slots on ground and cutting edges of patches. The measured result shows that 1.70 – 8.00 GHz (6.30 GHz) of IBW, 8.8 dBic of peak gain, and 3 dB axial ratio bandwidth from 1.81 – 3.87 GHz (2.06 GHz) are obtained. The proposed antenna performances are experimentally validated by fabricating and testing it for measured result analysis without using power divider.

Analysis of GFDM in generalized [formula omitted] fading channel: A simple probability density function approach for beyond 5G wireless applications

Generalized frequency division multiplexing (GFDM) is a flexible radio waveform which offers high degree of freedom in varying the number of time slots, number of subcarriers, and pulse shaping filters. In addition to this, it also covers orthogonal frequency division multiplexing (OFDM) and single carrier frequency domain equalization (SC-FDE) as corner cases. A well-known fact is that the performance of a wireless communication system is predominately effected by the characteristics of the fading environment. In this paper, symbol error rate (SER) closed-form expression of GFDM system under the generalized η−μ fading channel is derived. The proposed derivation includes Rayleigh, Nakagami-m, and Nakagami-q fading channels as special cases. A Mote-Carlo simulation test-bed is carried out using MATLAB to compare with analytical results and to validate the derived expressions based on the probability density function (PDF) approach. Further, this paper investigates the performance of the GFDM system by varying various parameters such as fading values, pulse shaping filters, roll-off factor, and modulation order. The detailed analysis suggests that the probability of SER is highly dependent on the above parameters. The results obtained are more useful in evaluating the performance of GFDM based communication system in a generalized manner.

Design of a microstrip antenna patch with a rectangular slot for 5G applications operating at 28 GHz

In this paper, we present a study and design of a rectangular-shaped microstrip patch antenna with a rectangular shaped slot at the operating frequency is 28GHz, for fifth generation (5G) wireless applications, using the microstrip line technique for feeding. The objective of this slot is to contribute to the improvement of antenna performance. This antenna is built on a Roger RT duroid 5880 type substrate having a relative permittivity equal to 2.2, a height of h = 0.5 mm, and a loss tangent of 0.0009. The compact size of this antenna is 4.2 mm × 3.3 mm × 0.5 mm. The simulations of this antenna were performed using high-frequency structure simulator (HFSS) and computer simulation technology (CST) software whose main purpose is to confirm the results obtained for this proposed antenna. The results obtained during these simulations are as follows: resonant frequency of 27.97 GHz and reflection coefficient ) of -20.95 dB, bandwidth of 1.06 GHz, a gain of 7.5 dB, radiated power of 29.9 dBm, and efficiency of 99.83%. These results obtained by this proposed antenna are better than those obtained from already existing antennas that are published in current scientific journals. Consequently, this antenna is likely to satisfy the needs for 5G wireless communication applications.

A single element of multiband switched beam antenna for 5G applications

This work proposes a simple design of switched beam antenna on square split-ring resonator to operate in multiband frequencies. The antenna is designed to support fifth generation (5G) wireless applications. The proposed antenna provides two different of the main beams, 45˚/225˚±5˚ and 135˚/315˚±5˚, by shorted circuit at 4 different edges. The designed antenna can support nine frequency bands, 7.071, 9.006, 9.321, 9.906, 10.428, 10.718, 12.967, 13.057 and 14.469 GHz, which are the high-band of 5G spectrum when shorted circuit to the ground conductor. The antenna provides maximum gain of 6.41 dBi. The dimension of the antenna is 6×6 mm<sup>2</sup> which the thickness of 1.73 mm. The proposed design is based on a simple beam switching antenna configuration, compact size and low-cost manufacturing.

A low power, highly efficient, linear, enhanced wideband Class-J mode power amplifier for 5G applications

In wireless communication networks, the necessity for high-speed data rates has increased in emerging 5G application areas. The Power Amplifier (PA) topologies reported to date achieved desired Power Added Efficiency (PAE) and linearity. However, these harmonically tuned switching PAs are less appealing for broadband applications as they are restricted to narrow bandwidth (BW). Therefore, to meet the 5G requirements, the challenge of designing a PA with improved efficiency and linearity for a dynamic range of BW becomes critical for PA designers. Recently developed Class-J PA topology can obtain good efficiency while maintaining linearity for wide BW applications. This research work presents a methodology to design a 5 GHz Class-J mode PA topology using Silterra 0.13 μm CMOS technology. This research's main objectives are to determine the Ropt of the transistor and design a proper Output Matching Network (OMN) for obtaining Class-J PA operation to make it suitable for 5G wireless applications. The simulation results represent that the designed Class-J PA provides 27 dBm of maximum power output with a maximum power gain of 13.7 dB and the small-signal gain of 17 dB for a BW of around 500 MHz with a 5 V power supply into a 50Ω load.

Designing of Solid State SIW Antenna for 5G Application

This experimental research paper presents the plan of a solid single band microstrip patch Substrate Integrated Waveguide(SIW) antenna, which might be suitable candidate for 5G wireless application working at 3.5GHz. Right now, the full world is within the surge of satisfying the request of capacity boosting highlights of remote eras, such as huge data rate in conjunction with moo inactivity, ultra-reliable communications, and enormous network. These all over said highlights of 5th era remote innovation might be for the most part held within the 3.5GHz band. The plan of SIW antenna proposed in this paper is carried on Roger RT3203 with 3.02 dielectric, 0.0016 misfortune digression, and 1 Oz thickness utilizing inset bolstering. The overall dimension of the patch antenna is 60.4523×34mm2. In this work, rectangular fix is planned with U-shape opened radio wire with utilizing SIW methodology. The antenna is outlined and recreated and the investigation was carried out on Computer Simulation Technology (CST) studio. The antenna attains gain of 2.61dB at 3.5GHz frequency, which is the most preferred feature that facilitates to implement this antenna plan in the 5G applications.

Design of a Source Degenerated Cascode Stage Low Noise Amplifier for 5G Applications

Low Noise Amplifier (LNA) is the most critical part of a receiver front end in terms of the receiver performance. The performance tradeoff among input matching, noise figure, gain, and linearity are analyzed in detail. The LNA finds its application at Portable GPS Receiver, BLE, Zigbee, NFC, WiFi, Wireless Sensor Network, RFIC operating at 2.4GHz frequency. Millimeter wave communication is an evolving technology for bandwidth demanding 5G wireless application. A high gain and linear narrowband cascode Low Noise Amplifier (LNA) operating at 2.18GHz to 2.47GHz is proposed. To demonstrate design methodology, a narrow-band source degenerated cascode LNA is designed and simulated in a standard 90nm CMOS process to operate in the 2.4 GHZ band. The LNA achieves a voltage gain of 5.38dB, Noise figure of 4.1127dB, and from 3.2 V supply voltage. Proper input and output impedance matching have been performed to achieve the input return loss of -14 dB (S11) and output return loss of -19.72 dB (S22). Simulation study has been done using Cadence spectre.

Frequency Integration of Dual-band Hexagonal Metamaterial Resonator antenna for Wi-Fi and 5G Wireless Communication

Abstract The integration of 5G mm-wave and Wi-Fi frequency bands becomes significant for upcoming 5G wireless applications for providing a large frequency ratio. This work presents a frequency reconfigurable hexagonal metamaterial resonator (HMR) antenna for Wi-Fi and a 5G mm-wave frequency band. A PIN diode is utilized to link up a microstrip patch antenna (MPA) with HMR to achieve integration of the Wi-Fi frequency band. The resonant frequency of the proposed antenna is 5 GHz (Wi-Fi) and 27.87 GHz with peak gain 2.33 dB and 7.12 dB, respectively. The operating bandwidth of the proposed antenna is 800 MHz (4.5-5.3 GHz) and 1020 MHz (27.35-28.37 GHz). The rogers RT5880 substrate with thickness 0.508 mm, dielectric constant 2.2, and loss tangent 0.009 has been used for designing the antenna. The overall size of the antenna is 30×23×0.508 mm3.

High-Isolation MIMO Antenna for 5G Millimeter-Wave Communication Systems

The work in this article presents the design and realization of a low-profile, four-port MIMO antenna supporting fifth-generation (5G) wireless applications operating at a millimeter-Wave (mm-Wave) band. Each MIMO antenna is a 2-element array fed with a corporate feeding network, whereas the single antenna is a patch with a bow-tie slot at the center and slits at the edges. The vertical and horizontal slots are incorporated as a Defected Ground Structure (DGS) to optimize the antenna performance. In addition, a slotted zig-zag decoupling structure is etched from edge to edge on the top side to enhance the isolation. Significant isolation (>−40 dB) is achieved between antenna elements by employing spatial and polarization diversity techniques. The proposed antenna covers the 5G mm-Wave band with a −10 dB bandwidth ranging from 27.6–28.6 GHz, whereas the maximum gain attained for the proposed structure is 12.02 dBi. Moreover, the lower correlation values, higher diversity gain, and lower channel capacity loss make it a suitable contender for 5G MIMO applications at the mm-Wave range.

28-GHz CMOS Direct-Conversion RF Transmitter with Precise and Wide-Range Mismatch Calibration Techniques

A millimeter-wave direct-conversion radio-frequency (RF) transmitter requires precise in-/quadrature-phase (I/Q) mismatch calibration and dc offset cancellation to minimize image rejection ratio (IRR) and LO feedthrough (LOFT) for ensuring satisfactory output spectral purity. We present a 28-GHz CMOS RF transmitter with an improved calibration technique for fifth generation (5G) wireless communication applications. The RF transmitter comprises a baseband amplifier, quadrature up-conversion mixer, power amplifier driver, and quadrature LO generator. The I/Q amplitude mismatch is calibrated by tuning the gate biases of the switching stage FETs of the mixer, the I/Q phase mismatch is calibrated by tuning the varactor capacitances at the LC load of LO buffer, and the dc offset is cancelled by tuning the body voltages of the differential-pair FETs at the baseband amplifier. The proposed technique provides precise calibration accuracy by employing mV-resolution tuning voltage generation via 6-bit voltage digital-to-analog converters. It also covers wide calibration range while minimizing the impact on the circuit’s bias point and dissipated current during calibration. Implemented in a 65 nm CMOS process, the RF transmitter integrated circuit shows output-referred 1 dB compression power of +6.5 dBm, saturated output power of +12.6 dBm, and an operating band of 27.5–29.3 GHz while demonstrating satisfactory performances of −55.9 dBc of IRR and −36.8 dBc of LOFT.

A Novel Meander Bowtie-Shaped Antenna with Multi-Resonant and Rejection Bands for Modern 5G Communications

To support various fifth generation (5G) wireless applications, a small, printed bowtie-shaped microstrip antenna with meandered arms is reported in this article. Because it spans the broad legal range, the developed antenna can serve or reject a variety of applications such as wireless fidelity (Wi-Fi), sub-6 GHz, and ultra-wideband (UWB) 5G communications due to its multiband characterization and optimized rejection bands. The antenna is built on an FR-4 substrate and powered via a 50-Ω microstrip feed line linked to the right bowtie’s side. The bowtie’s left side is coupled via a shorting pin to a partial ground at the antenna’s back side. A gradually increasing meandering microstrip line is connected to both sides of the bowtie to enhance the rejection and operating bands. The designed antenna has seven operating frequency bands of (2.43–3.03) GHz, (3.71–4.23) GHz, (4.76–5.38) GHz, (5.83–6.54) GHz, (6.85–7.44) GHz, (7.56–8.01) GHz, and (9.27–13.88) GHz. The simulated scattering parameter S11 reveals six rejection bands with percentage bandwidths of 33.87%, 15.73%, 11.71, 7.63%, 6.99%, and 12.22%, respectively. The maximum gain of the proposed antenna is 4.46 dB. The suggested antenna has been built, and the simulation and measurement results are very similar. The reported antenna is expanded to a four-element design to investigate its MIMO characteristics.

Design and performance analysis of a low-pull-in-voltage RF MEMS shunt switch for millimeter-wave therapy, IoT, and 5G applications

Recent advancements in wireless communication systems utilize miniaturized devices based on microelectromechanical system technology for present and future 5G wireless applications. Nowadays, RF devices are utilizing frequencies up to 30 GHz with substantial signal propagation that leads to a slow data rate. On the other hand, there is a huge spectrum available in the millimeter-wave frequency range of 30–300 GHz. The millimeter-wave spectrum is attractive for the development of smart systems based on 5G technology. In this paper, a low-pull-in-voltage capacitive type RF MEMS switch is proposed to operate at frequencies above 30 GHz. The switch is proposed with a new iterative meandering technique where the span length of each section in the meanders differs relative to the first section. A low pull-in voltage of 1.8 V is achieved with a large capacitance ratio of 63. The switch exhibits low insertion loss of −0.24 dB at 41 GHz and possesses high isolation of −46.7 dB at 38 GHz. The design is validated by comparing the theoretical and simulated results, and the switch can be efficiently utilized for millimeter-wave applications.

Dodecagon-Shaped Frequency Reconfigurable Antenna Practically Loaded with 3-Delta Structures for ISM Band and Wireless Applications

An edge fed, dual band, quarter-wave transformer coupled, monopole, ultra-wideband (UWB), dodecagon-shaped miniaturized frequency reconfigurable antenna for ISM and wireless applications is designed, analysed and investigated. The impedance transformer is utilized in the structure for impedance matching and hence results in lower reflection coefficient values. The antenna uses defected ground structure (DGS) in the bottom and radiating patch that is practically loaded with three numbers of delta structures. The use of DGS reduces the value of gain and provides ultra-wideband bandwidth across the designed frequency. The addition of three delta structures in the patch improves the value of gain. Miniaturizing in the size of the antenna has been achieved by reducing the ground along the width that led to a total 30.41% size reduction in the fundamental circular patch antenna. The antenna exhibits two bands 1.82–3.61 GHz and 5.24–12.43 GHz thus antenna is suitable for ISM band, PCS, 5G, Wi-Fi/WiMAX/WLAN and other wireless applications. The fabricated antenna is frequency reconfigured by utilizing the switching property of four numbers of PIN diodes (BAP64-02V). Frequency reconfigurable antenna is used flexibly and versatile for various microwave applications based on the switching conditions (more than eight digital combination cases) of PIN diodes. The prototype measured results provide good agreements with the simulated reflection coefficients values in some mode of operations. Antenna radiating patch and ground is etched on FR-4 substrate of dimension 52 mm × 59 mm × 1.6 mm using printed circuit board technology.

A Compact Frequency and Radiation Reconfigurable Antenna for 5G and Multistandard Sub-6 GHz Wireless Applications

This paper presents a reconfigurable antenna operating in three modes at different frequency bands with pattern reconfiguration. Frequency and pattern reconfigurability are achieved using four PIN diodes. In particular, two diodes are mounted in the radiating part of the hexagon shape to perform the frequency reconfiguration of the antenna. The other two PIN diodes are connected with the inverted L-shaped and CPW ground by changing the main lobe beam steering to achieve the pattern reconfiguration. An antenna has been designed, fabricated, and numerically and experimentally assessed. The prototype of the antenna is fabricated on a commercially available FR-4 substrate of thickness 1.6 mm ( ε r = 4.3). Thus, the proposed antenna supports several 5G sub-6 GHz bands (3.1 GHz, 4.1 GHz, and 3.8 GHz), WiFi (2.45 GHz), as well as (7.8 GHz, 9.5 GHz) X-Band Satellite applications. The obtained results are quite promising. In particular, it is observed that the measured results are in close agreement with the simulation results, and the proposed (compact) antenna prototype can be a prospective candidate for future portable devices, sensor networks, and telecommunication applications.

An energy efficient resource allocation and transmit antenna selection scheme in mm‐wave using massive multiple‐input multiple‐output technology

SummaryThe massive multiple‐input multiple‐output (MIMO) improves the reliability of transmission and capacity of the channel. Resource allocation (RA) and transmit antenna selection (TAS) can minimize the complexity in implementation and hardware costs. In this research, both the RA and the TAS of wireless communication in millimeter‐wave (mm‐wave) with massive MIMO technology are considered. Two different solutions are developed for this research such as the deep learning method for efficient resource allocation process and optimization algorithm for TAS process. Here, the RA process is done with the help of attention‐based capsule auto‐encoder (ACAE) architecture which allocates the radio resources like power, space, time and frequency to all the available users in the system. Further, battle royale optimization (BRO) algorithm is utilized to select an efficient antenna from multiple antennas at BS. This optimization algorithm optimally selects an efficient antenna so that, user equipment (UEs) can create high quality links and achieves a reduced power consumption rate of the whole architecture. The overall system performance depends on the selection of optimal antenna which in terms enhances spectral efficiency (SE), energy efficiency (EE), reliability, and diversity gain of MIMO technology. In this way, both RA and optimal antenna selection schemes are performed to maximize the overall performance of wireless communication with massive MIMO technology for 5G wireless communication applications. The implementation of the proposed methodology is evaluated on MATLAB. Finally, the efficiency of the developed method is improved with respect to the capacity, EE, and SE.

Multiband Reconfigurable Antennas for 5G Wireless and CubeSat Applications: A Review

The rapid development of wireless technology has sparked interest in multi-band reconfigurable antennas as devices and satellites are innovating toward miniaturization. With limited space, reliable and efficient high bandwidth antenna systems are needed for current and next-generation wireless technology as well as for the revolutionary small satellites. The fifth generation of mobile communication technology promises high data rates, low latency and good spectrum efficiency. One of the key enablers of this technology is the integration of satellite technology-particularly CubeSats with terrestrial communication technologies. Next-generation antennas that can meet functional requirements for 5G and CubeSat applications are therefore of fundamental importance. These antenna systems should have large bandwidth, high gain and efficiency and be compact in size. Reconfigurable antennas can provide different configurations in terms of the operating frequency, radiation pattern and polarization. Tuning reconfigurable antennas can be done by changing the physical parameters of the antenna elements through electronic switches, optical switches and the use of meta-materials. The most popular implementation method for reconfigurable antennas for wireless and satellite communication is the electronic switching method due to its high reliability, efficiency, and ease of integration with microwave circuitry. In this article, different techniques for implementing reconfigurable and multi-band antennas are reviewed, with emphasis on two main application areas; 5G wireless communication and CubeSat application. Different reconfiguration techniques have been studied for application in various wireless communication systems such as satellite communication, multiple-input multiple-output (MIMO) systems, cognitive radio and 5G communication. It has been found that reconfigurable antennas have favourable properties for next-generation wireless technology and small satellites. These properties include low cost, less volume requirements and good isolation between wireless standards.

A Review of Low Profile Single Layer Microstrip Antennas

The modern wireless systems call for integrating multiple applications. There are numerous techniques available to cater these demands. However the need for thin, light weight and compact wireless applications call for the design of low profile and single layer antennas with multiple features. Hence, this paper deliberates on the comprehensive review of compact, low profile, and single layer microstrip antennas suitable for fifth generation (5G) wireless applications, wireless local area network (WLAN), worldwide interoperability for microwave access (Wi-Max), and other state of the art wireless applications. The techniques discussed here consider the performance improvement of one or more parameters of the antenna. These parameters include the improvement of impedance (10dB return loss) bandwidth, gain, 3dB axial ratio (AR) bandwidth, improvement of isolation between the ports in multiple input multiple output (MIMO) antennas, and excitation of dual modes/dual polarization/circular polarization. Antennas with all such techniques and their advantages, applications & limitations have been discussed in detail. The studies presented here on single layer planar antennas offer a maximum impedance bandwidth of up to 68%, highest axial ratio bandwidth of 46%, and 11.6dBi gain for single element & 25.6dBi gain for arrays. Other significant findings covered are antennas with triple bands operation, arrays with less than -37.5dB mutual coupling and compact antennas with more than 60% reduction in physical area. In addition to the advantages and applications, their limitations and drawbacks are also discussed.

Dual Band Switched Beam Textile Antenna for 5G Wireless Communications

This paper presents the single element dual band switched beam textile antenna. The antenna can operate at frequencies of 0.7 and 2.6 GHz using for 5G wireless communication applications. Textile fabric is considered to be used for substrate layer at the parts of a microstrip antenna for wireless body area network. The beam pattern of antenna can be switched into two directions by changing the position of shorted-circuit points at each edge of antenna. The main beam direction is 45°/225° when corner A is shorted while it steers at 135°/315° when corner B is shorted circuit. The advantage of the proposed antenna is the decrease of the problems like interference, light weight, flexibility and ability to switch beam easily. In addition, the results of the fabricated antenna are compared with the simulated ones. Moreover, the antenna is bent with curvature radius of 6 mm in forward direction. The effects of the bent antenna are studied. The results can confirm that radiation patterns of the bending antenna can be pointed into two directions when changing the positions of shorted circuit. Therefore, the proposed antenna can switch beam patterns, it is flexible, and it can operate at dual-band frequency on textile.

Pentagonal-shaped slot two port MIMO antenna for sub 6 GHz 5G wireless applications

In this paper, two-element multiple-input-multiple-output (MIMO) antenna system is presented for future sub-6 GHz 5G applications with improved impedance matching and isolation. In first design, a single rectangular patch antenna of 16.76 mm × 14 mm with pentagonal shaped slot and defected ground structure is proposed with a gain of 2.79 dB for WLAN (5.2 GHz) application. Second design consist of two elements MIMO patch antenna of dimension 16.76 mm × 47 mm × 1.6 mm on front side and defected ground structure on the back side of a FR4 substrate. The resonance frequency of antenna is 5.2 GHz with S11 = S22 = −26.47 db and good isolation between two ports and gain is 6.83db. Simulation has been performed on CST studio suite.

Recent Developments of Butler Matrix From Components Design Evolution to System Integration for 5G Beamforming Applications: A Survey

Beamforming networks for multiple beam antennas are believed to be in the vanguard of technological developments in mmWave for 5G wireless applications. The basic idea of beamforming technique is the application of multiple antenna elements radiating the same signal at an identical phase and wavelength, into one strong signal pointed to a specific direction. For low cost and power consumption, radio frequency beamforming networks (RF-BFNs) such as Blass matrices, Butler matrices, and Nolen matrices will play a critical role in achieving the ever-increasing demands in wireless technology. Therefore, this study aims to present a comprehensive survey and developments of RF-BFNs with (particular focus in Butler matrices). From the fundamental perspectives of the beamforming techniques and progress over time, component evolution includes branch-line coupler (BLC), Phase shifter (PS), and Crossovers to complete system Butler matrix (BM) integration. Different design techniques to improve bandwidth, size reduction, multi-band, and other performance characteristics are discussed extensively. Furthermore, the paper also discusses different geometry of Butler matrices in open microstrip transmission lines, substrate integrated waveguide (SIW) and gap waveguide (GWG) technologies highlighting key developments and research challenges from single band to dual-band operations.We expect this paper to provide more profound insights into the designs processes and suggest suitable ways to facilitate further developments of RF-beamforming networks at mmWave and sub-mmWave frequency ranges.