5G Bands Research Articles

A Wideband Circularly Polarized Four Port Microstrip MIMO Antenna with High Gain and Enhanced Isolation for 5G Millimeter Frequency Applications

Abstract In this article, a MIMO antenna system featuring wide bandwidth, high gain, and circular polarization for 5G communication networks is presented. The proposed antenna enables high data rates, enhanced signal reliability, and improved performance in dynamic and challenging 5G environments. Wide bandwidth ensures compatibility with various 5G frequency bands, while circular polarization allows for better signal propagation and reception, particularly in non-line-of-sight scenarios. In that regard, the present endeavor exhibits an enhanced bandwidth 4-port circularly polarized MIMO antenna to encounter polarization mismatch along with high data rates. The presented MIMO antenna comprises four identical patches strategically positioned in orthogonal orientations in such a way as to provide the circular polarization direction. Meanwhile, the bandwidth is extended by inserting straightforward defected ground structure (DGS) and L slots. The MIMO antenna anticipated in this work offers an impedance bandwidth covering from 24 GHz to 28.5 GHz and an axial ratio bandwidth of 62% within the overall band. It demonstrates excellent performance with a high peak gain of approximately 14.84 dB. Additionally, it exhibits strong isolation of more than 20dB among the closely packed antennas, ensuring reliable communication and minimizing interference. The combination of these features in a MIMO antenna system is crucial for meeting the demanding requirements of 5G communication, including increased data capacity, low latency, and reliable connectivity. The simulated and measured outcomes exhibit robust concurrence, signifying a high level of accuracy. Consequently, the suggested MIMO antenna appears well-suited for encompassing the 5G bands designated for deployment in the USA (27.50–28.35 GHz) and Europe (24.25 - 27.5 GHz).

A novel artificial intelligence‐based antenna designing model for optimizing 5G mobile communication

AbstractAntenna designing involves the creation of devices to transmit or receive electromagnetic signals for various applications. It encompasses optimizing parameters such as size, shape, and frequency response to achieve desired performance characteristics, including signal strength, bandwidth, and efficiency, across diverse communication systems and frequencies. In this research, we intend to establish a novel artificial intelligence (AI)‐based antenna designing model for optimizing 5th generation (5G) mobile communication. We proposed Multi‐Objective Zebra Optimization (MOZO) to enhance 5G antenna design, aiming to minimize return loss () and maximize gain (G) concurrently. MOZO efficiently explores design space, offering Pareto‐optimal solutions that balance objectives. This approach ensures optimal antenna performance across the desired frequency range, advancing 5G communication efficiency. Our model enhances the functionality of a small, rectangular patch antenna designed for the 5G band, specifically operating at 30 GHz. Additionally, we conducted a comparative analysis between the performance of our optimized rectangular 5G antenna and several recently employed 5G‐millimeter wave (mmWave) antennas. This comparison sheds light on the efficacy and competitiveness of our optimized design within the 5G‐mmWave antenna landscape.

Effective area reduction & surface waves suppression of a novel four-element MIMO antenna exclusively designed for dual band 5G sub 6 GHz (N77/N78 & N79) applications

Effective area reduction & surface waves suppression of a novel four-element MIMO antenna exclusively designed for dual band 5G sub 6 GHz (N77/N78 & N79) applications

Design and Analysis of Sierpinski Fractal Antennas for Millimeter‐Wave 5G and Ground‐Based Radio Navigation Applications

ABSTRACTThe paper describes compact fractal antennae combined with ground defected structures (DGS) and substrate integrated waveguide (SIW) techniques for enhancing resonate and multiband behavior concerning bandwidth, gain, and radiation in the desired mm‐wave region. Based on the proposed antennae, multiple good notches over wide bands depict a good radiation pattern. The antennae's ultra wide bandwidths (UWB) are 16, 16, and 11.4 GHz concerning resonant frequencies 26.34, 30.35, 34.5, 36.65 GHz; 25.8, 32.2, 35.3 GHz; 30.22, 37.68 GHz, of concerning antennae ant 1 (FA1), 4 (FA2), and 6 (FA3), respectively. The proposed antenna (FA3) with the SIW technique has a peak gain of 5.9 dBi and a peak front‐to‐back ratio of 20 dB, respectively. The proposed antennas are targeted to cover the practical contribution aspect, including advanced 5G bands support (24–40 GHz), broadband spectrum, frequency agility, low 3 dB beamwidth, interference reduction, and medical application suitability, respectively. The proposed antennae also cover the desired mm wave 5G region with different resonating notches over ultra‐wide bandwidth, such as n257, n258, n259, n260, and n261, and ground‐based radio navigation applications. Results are validated with vector network analyzer, spectrum analyzer, and power sensor in the presence of absorber, respectively.

Design of highly selective ultrawideband FSS based on deep learning for EMI shielding in 5G bands

Abstract In this paper, a frequency selective surface (FSS) for n41, n78, n257, n258, n260, and n261 bands electromagnetic interference (EMI) shielding is proposed using a deep learning method. The size of the FSS unit cell is 4.8 mm (0.071 λ 0 ), where λ 0 is the wavelength corresponding to the cutoff frequency of the −10 dB stopband where the n41 and n78 bands are located. This FSS exhibits three key characteristics. Firstly, it possesses ultrawideband capability, with a stopband frequency range of 23.922–40.023 GHz and a relative bandwidth reaching 50.4%. Secondly, it effectively shields against electromagnetic radiation in multiple 5 G bands, including n41, n78, n257, n258, n260, and n261. Thirdly, it demonstrates high selectivity, with a very narrow transition band of only 0.405 GHz between the passband and the stopband. To validate the designed FSS, a prototype of this structure was first fabricated for experimentation. The experimental results show that the measured S21 is highly consistent with the simulated S21. Secondly, the unit cell array of FSS is placed above the monopole antenna for co-simulation. It can be observed that after placing the FSS, the intensity of electromagnetic radiation propagating in space is significantly reduced by up to more than 90%. Therefore, the proposed FSS can be effectively applied for EMI shielding in 5 G bands.

A Novel 5G Multi-mode Resonator and Filter with Symmetric Transmission Zeros

5G construction is becoming increasingly important. This paper introduces the theoretical basis of multi-mode filter, and on the basis of theoretical calculation and analysis, a novel 5G cavity multi-mode resonator and filter is designed by using ads/HFSS simulation software. The electric field characteristic of resonator is analyzed, and the mutual coupling between modes is realized by the way of screw perturbation. The electric field distributions of the mode is changed by adding tuning screws, two coupled degenerate modes act as two coupled resonators, so that the numbers of resonator can be reduced while keeping the resonance loop unchanged. For example, the characteristics of 3N section filter can be realized in the physical space of a traditional n-section filter by using three modes of a resonator, thus greatly reducing the volume of the filter. The results show that in the pass-band (3.5 GHz ~ 3.6 GHz): return loss > 17.9 dB, standing wave ratio < 1.29, insertion loss < 0.31 dB, a transmission zero point is introduced at 4 GHz on the right side of the pass-band, which makes the right side out of band attenuation rapidly. The filter has the advantages of small insertion loss, small size and good rejection of out of band, which can be applied to 5G band wireless communication system for better reliability.

Gain enhancement of mm-wave antenna using graded index lens integrated frequency selective surface for 5G NR FR2 applications

In this study, the gain of a printed antenna is boosted for utilization in 5G systems by employing a phase-oriented graded index-type lens system. In the prescribed design, various metamaterial unit cells are arranged as arrays with radial phases for the graded meta lens to optimize transmission characteristics. The suggested arrangement creates a meta lens with spatially varying surface impedance and locally varying refractive index, allowing the conversion of spherical wavefronts into planar wavefronts for beam collimation in the 5G band. The focal length-to-diameter ratio (f/d) is fixed at 0.38 in this prescribed design. The integration of the FSS structure with the patch antenna enhances the efficiency above 98% and increases gain by 2.635dBi owing to the focusing effect of the properly placed lens. The prescribed planar lens is easy to realize during manufacturing compared to 3D lenses. The meta lens integrated patch yields a gain of around 8.936dBi at 29 GHz. The performance of the lens antenna is evaluated through simulation studies and then validation of results is performed with experimental arrangement to ensure accuracy and reliability of the suggested methodology for gain enhancement of the functioning antenna at FR2 5G spectrum.

Multilayer multiband hybrid fractal antenna for public safety and 5G Sub-6 GHz bands

In this work, a multiband hybrid fractal antenna is developed for public safety and 5G Sub-6 GHz bands. Proposed antenna design is designed, analyzed, and optimized using HFSS simulator. Radiating element of the proposed antenna consists of Hybrid Fractal shape which is designed using Koch and Hilbert curve fractal geometry. Hybrid Fractal Antenna (HFA) is designed on a Multilayer FR4 substrate which has an overall size of 0.22 × 0.47 × 0.044 ƛ3. Parametric analysis of the proposed design is done to get the optimum results. Proposed HFA resonates at 2.64 GHz (2.34–2.80 GHz), 3.87, 4.54, 5.02, 5.35 GHz (3.73–5.55 GHz), and 6.42 GHz (5.70–6.72 GHz) with a gain of 4.2, 0.9, 2.9, 3.3, 4.6, and 3.7 dBi respectively. The proposed HFA is useful for 5G bands such as: N7 band, N38 band, N40 band, N41 band, N47 band, N53 band, N79 band, N90 band and N93 band, and also useful for public safety band (4.9 GHz). Prototype of the proposed HFA is fabricated and tested in lab for the verification of simulated results. The results show good performance in terms of reflection coefficient, gain, and bandwidth. Measured results are in good agreement with the simulated results.

Parametric Synthesis of Single-Stage Lattice-Type Acoustic Wave Filters and Extended Multi-Stage Design.

This study proposes a single-stage lattice-type acoustic filter using an analytical solution method for either a narrow passband filter or a wider passband filter using two kinds of parameter assignments in the Butterworth-Van Dyke (BVD) model. To achieve the goal of a large bandwidth or high return loss, two first-order all-pass conditions are used. For multi-stage lattice-type filters, the cost function is defined and design parameters are extracted by using pattern search, while the initial values are provided through single-stage design to shorten optimization time and allow convergence to a better solution. This method provides the S-parameter frequency response for the filter on the YX 42° cut angle of lithium tantalate (electromechanical coupling coefficient of about 6%) that can meet the system specifications as much as possible. Finally, the three-stage lattice-type was applied to various 5G bands with a fractional bandwidth of 2-5%, resulting in a passband return loss of 10 dB and an out-of-band rejection of 40 dB or more.

High-Efficiency 5G-Band Rectifier with Impedance Dispersion Compensation Network

This paper proposes a microwave rectifier designed for the popular 5G band, featuring impedance dispersion compensation and a cross-type impedance matching network. The rectifier has an ultra-high power conversion efficiency. The compensation network employs two parallel transmission lines to counteract the nonlinear shift of the diode input impedance caused by frequency variation. Additionally, the cross-over impedance matching network enhances matching and minimizes losses. After rigorous theoretical analysis and simulation, the rectifier is fabricated. Experimental results show significant conversion efficiency in the 5G band (across 4–6.5 GHz). At an input power of 12 dBm, the rectifier achieves more than 60% efficiency between 4.8 and 6.4 GHz and more than 70% between 5.2 and 6.2 GHz, with a peak efficiency of 78.1%. Moreover, the rectifier maintains more than 50% efficiency over a wide input power range of 5 to 14 dBm.

Efficient rectifier with wide input power range for 5G applications

This article presents three efficient rectifiers for radio frequency energy harvest-ing (RFEH) systems operating at the fifth generation (5G) band (3.5 GHz). Eachrectifier operates at various input power levels (high, low, and across a widepower range). The high and low-power rectifiers feature a single serial topologyusing HSMS-2860 and SMS-7630 Schottky diodes, respectively, along with mi-crostrip lines to implement the input and output filters and the impedance match-ing network. At an radio frequency (RF) power level of 15 dBm, the high-powerrectifier harvests 67.4% to direct current (DC) power with a 300Ωload resistorand an output voltage of 2.5V. The low-power rectifier achieves its maximumpower conversion efficiency (PCE) at -2 dBm, reaching 45% efficiency with a1200Ωload. The rectifier with a extended input power range comprises twobranches of subrectifiers functioning at both high and low power levels. De-pending on the power level, the considered subrectifier harvests radio frequencypower into DC power, while the other subrectifier is deactivated. Across a powerspan of 32.5 dB (ranging from -13 to 19.5 dBm), the rectifier maintains an effi-ciency above 30%. The proposed rectifiers are efficient and suitable for imple-mentation in 5G-enabled RFEH systems.

Analysis and design of compact dual-mode bandpass filter based on modified CSRR with wide stopband for 5G sub-6 GHz mobile communications

In this paper, a dual-mode bandpass filter with a wide stopband based on modified complementary split-ring resonators for 5G sub-6 GHz mobile communications is presented. The non-magnetic resonant particle known as a complimentary split ring resonator is used with a host microstrip line with a series gap in order to obtain a bandpass response. Since a complementary split-ring resonator provides a narrow passband, a T-slot has been introduced in the middle of this resonator to obtain dual-mode behavior with controllable bandwidth. Moreover, a pair of stubs are added to the host microstrip line in order to achieve a wide stopband with good out-of-band rejection. The proposed resonator is analyzed, and a bandpass filter is designed to operate at 3.6 GHz to cover the 5G band from 3.4 to 3.8 GHz. The results show that the filter has a low insertion loss, good return loss, and a wide stopband up to 9 GHz with a compact size since its resonator offers a size of 0.1 λ g × 0.14 λ g where λ g is the guided wavelength at 3.6 GHz.

Eight element MIMO antenna for sub 6 GHz 5G cellular devices

This article introduces a wide-band MIMO antenna system with eight elements specifically designed for future handheld devices. The antenna is integrated into a 150 × 75 mm2 main board with a DGS antenna beneath it, connected to feed lines, and etched onto the ground plane. Covering two distinct 5G bands from 3 GHz to 3.6 GHz and from 3.6 GHz to 3.9 GHz, with 900 MHz impedance bandwidths, this antenna enables efficient data transmission and reception across these crucial frequency ranges. The system exhibits pattern and spatial diversity characteristics, achieving an overall efficiency of 40%–60% and a peak gain of 5.3 dBi, ensuring robust signal strength and isolation exceeding 10 dB among radiating elements. Furthermore, the antenna excels in key MIMO parameters, with an envelope correlation coefficient (ECC) below 0.19, well within the industry standard of less than 0.5, and it delivers more than 9.99 dB of diversity gain. Furthermore, Channel capacity Loss (CCL), Mean Effective Gain (MEG) and Total Active Reflection Co-efficient (TARC) across the entire operational band ensure good performance, promising enhanced diversity performance, superior data throughput, and heightened signal reliability. are The SAR analysis conducted yielded positive results within the human vicinity. The measurements obtained from the prototype matched well with simulations and through measurements obtained the proposed MIMO system can be termed as a potential candidate for future 5G Mobile Phones.

Compact, Ultra-Wideband Butler Matrix Beamformers for the Advanced 5G Band FR3—Part I

Butler Matrix networks are well established as beamforming networks for phased antenna arrays. The challenge we address in this work is to cover the entire (advanced 5G or 6G) FR3 band (7–24 GHz) with a single network, while retaining low losses and minimal size. The employed multilayer topology is also well established; however, the matching between the utilized hybrid couplers and the phase shifters constitutes a major challenge for such a wideband operation. This is achieved herein by employing meander lines with appropriate curvature and introducing two distinct design methods for the Butler Matrix. The first method focuses on designing individual components separately, followed by their integration into the overall Butler Matrix structure. This approach is demonstrated through the design, prototyping, measurements, and validation of an 8 × 8 Butler Matrix beamformer, which operates across the 6–16 GHz band (FR3 Low). The second method introduces a wideband-matching technique which simplifies the implementation process by designing the Butler Matrix as a single, unified structure. This technique is applied to both 4 × 4 and 8 × 8 Butler Matrices, which are implemented and simulated for the low FR3 band. Both design methods result in wideband operation and compact size and meet the desired performance criteria.

Compact IPD bandpass filter with wide upper stopband based on modified topology for 5G applications

AbstractA compact bandpass filter (BPF) with wide stopband performance is proposed and implemented on Si‐based integrated passive device (IPD) technology. A modified topology consisting of a novel Pi‐section and two capacitors are introduced in this BPF. The Pi‐section topology can achieve a band‐pass performance and generate four transmission zeros out‐of‐band. These two capacitors can improve the in‐band matching and also widen the stopband. The proposed BPF with a compact size of 1.0 mm × 0.5 mm × 0.3 mm is fabricated using Si IPD technology and measured by on‐wafer probing. It shows that the insertion loss is less than 1.75 dB, the return loss is better than 18 dB in the 5G band, and the upper stopband suppression level is better than 17.5 dB up to 18 GHz. The simulated and measured results of the proposed BPF are in reasonably good agreement.

Design and Fabrication of Compact MIMO Array Antenna with Tapered Feed Line for 5G Applications

In this paper, we design, fabricate, measure, and report two proposed multiple input multiple output antenna elements (MIMOs) with good performance in the 5G band. The MIMO antennas are mounted on Roger / Druoid 5880 substrates (dielectric constant: 2.2) with an overall structure volume 20×24.14×0.79mm3. First, a comprehensive parametric study is performed based on CST Electromagnetic (EM) Simulator to investigate and enhance the antenna performance in relation to 5G application requirements. Second, as part of the antenna design process, we compute the envelope correlation coefficient (ECC > 0.01dB) and diversity gain (DG> 9.9dB) and achieve good results. Third, we provide fabrication and measurement verification with good agreement. Fourth, we use a tapered feed structure with inset feed to minimize mutual coupling and achieve matching along 2 transmission lines with various impedances with high compactness in the antenna structure. Fifthly, we report that the proposed antenna structure has a gain is 8 dBi (dB) at the relevant operating frequency band (24.25

LCP-Based Low-Cost Base Station Antenna for 3.7 GHz 5G Band

This paper presents a large-scale base station antenna assembly structure that is low-cost, reliable, and easy to manufacture. The antenna element is composed of a low-loss liquid crystal polymer based on a plastic molded module and a modified wideband stacked patch antenna. The base station antenna consists of a 4 × 8 antenna module, with each module comprising 3 × 1 subarrays along with dual-polarized antenna elements. The antenna element achieved an efficiency of 91% and an impedance bandwidth of 1.14 GHz within a height of 10 mm at 3.7 GHz. Furthermore, the fabricated array antenna structure was tested and verified to have an effective isotropic radiated power of 75.6 dBm at boresight and a steering range of less than ±60°. Therefore, the proposed structure meets the required antenna and beam-forming performance for commercial 5G active antenna systems.

Tri-band antenna with metasurface-based ground plane for Sub-6 GHz 5G and 6G WPT applications

In this paper, a spiral-shaped metamaterial-loaded rhombic slotted microstrip patch antenna is investigated for Sub-6 GHz 5G and 6 GHz tri-band applications. A 1.524 mm thick Rogers RO4003 substrate (ϵr = 3.55, LosTanδ = 0.0027) opts for the antenna design. A partially grounded mechanism is implemented to control the operating frequencies of the antenna. A 5×5 triangular unit cell metasurface is deposited beside the partial ground plane to enhance the impedance bandwidth as well as to improve the impedance matching. A G-shaped metallic structure enclosed within the rhombic slotted antenna helps in creating circular polarization (CP) properties. The presented antenna resonates at 3.28 GHz (Mid-range Sub 6 GHz 5G band), 4.94 GHz (Upper range Sub 6 GHz 5G band), and 6.92 GHz (Sub 6 GHz 6G Band) frequencies. The maximum gain offered by the antenna is 8.81 dBi. Also, the developed antenna offers CP characteristics in all three operating bands with wide axial ratio (AR) bandwidth characteristics above 400 MHz in both the first and third operating bands. The radial characteristics of the proposed antenna show its capability of receiving EM signals from all directions as desired for a WPT system. For validation purposes, a prototype is fabricated and characterized as well.

Metamaterial-Inspired Electrically Compact Triangular Antennas Loaded with CSRR

In this paper, simulation of two distinct kinds of metamaterial (MTM) antennas are proposed for fifth generation (5G) indoor distributed antenna systems (IDAS). Both antennas operate in the sub-6 GHz 5G band, i.e., 3.5 GHz and to analyze various factors like gain, directivity, return loss, radiation intensity for the frequency of 3.5 GHz. The simulation of this metamaterial antenna is carried out in ANSYS HFSS v2021. Results like return loss, radiation pattern, 3D polar plot, side lobe level, beamwidth, radiated power, accepted power have been obtained using HFSS v2021. This research on metamaterial gives a great view on how it can be designed and used at 3.5GHz frequency has a measured gain/bandwidth characteristic of 100 MHz/2.6 dBi and 700 MHz/2.3 dBi, respectively. The main advantage of this antenna is it can be used as both transmitting and receiving antenna. Key Words: Metamaterial, CSRR, return loss, triangular CSRR

Printed Dual Band Antenna with Parasite Elements for LTE and 5G Applications

A printed antenna for long-term evolution (LTE) band (1.71–1.755 GHz) and 5G band (3.3–3.8 GHz) has been investigated in this article. A balanced feeder line is employed to feed the radiating element at the 5G band of operation, which becomes a radiator at the LTE band. The measured reflection coefficient (S11≤−10 dB) bandwidth is 6% (LTE band: 1.67–1.776 GHz) and 30.76% (5G band: 2.875–3.92 GHz). This antenna radiates with a gain of 3.25 dBi at the LTE band in the broadside and 6.5dBi at the 5G band in the end-fire direction. An open-ended tuning stub is used to tune out the reactance of the radiating element to enhance its radiation and act as a reflector to enhance the directivity in the 5G band. The printed parasite strip forces the beam towards the axial direction (end-fire) and enhances the gain in the 5G band. Both bands form an orthogonal radiation pattern. This antenna can also be utilized for WiMAX (3.5 GHz) band applications.