Long Term Evolution Band Research Articles

Effects of 4G Long-Term Evolution Electromagnetic Fields on Thyroid Hormone Dysfunction and Behavioral Changes in Adolescent Male Mice.

Radiofrequency electromagnetic fields (RF-EMFs) can penetrate tissues and potentially influence endocrine and brain development. Despite increased mobile phone use among children and adolescents, the long-term effects of RF-EMF exposure on brain and endocrine development remain unclear. This study investigated the effects of long-term evolution band (LTE) EMF exposure on thyroid hormone levels, crucial for metabolism, growth, and development. Four-week-old male mice (C57BL/6) were exposed to LTE EMF (whole-body average specific absorption rate [SAR] 4 W/kg) or a positive control (lead; Pb, 300 ppm in drinking water) for 4 weeks. Subsequently, the mice underwent behavioral tests including open field, marble burying, and nest building. Blood pituitary and thyroid hormone levels, and thyroid hormone-regulating genes within the hypothalamus-pituitary-thyroid (HPT) axis were analyzed. LTE exposure increased T3 levels, while Pb exposure elevated T3 and T4 and decreased ACTH levels. The LTE EMF group showed no gene expression alterations in the thyroid and pituitary glands, but hypothalamic Dio2 and Dio3 expressions were significantly reduced compared to that in the sham-exposed group. Pb exposure altered the hypothalamic mRNA levels of Oatp1c1 and Trh, pituitary mRNA of Trhr, and Tpo and Tg expression in the thyroid. In conclusion, LTE EMF exposure altered hypothalamic Dio2 and Dio3 expression, potentially impacting the HPT axis function. Further research is needed to explore RF-EMF's impacts on the endocrine system.

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.

Trust region framework-based design of sub-6 GHz m-MIMO antenna and evaluation of SAR

PurposeCurrently, massive multiple-input multiple-output (m-MIMO) antennas are typically designed using complex trial-and-error methods. The purpose of this study is to determine an effective optimization method to achieve more efficient antenna design processes.Design/methodology/approachThis paper presents the design stages of a m-MIMO antenna array compatible with 5G smartphones operating in long term evolution (LTE) bands 42, 43 and 46, based on a specific algorithm. Each antenna element in the designed 10-port m-MIMO antenna array is intended to perfectly cover the three specified LTE bands. The optimization methods used for this purpose include the Nelder–Mead simplex algorithm, covariance matrix adaptation evolution strategy, particle swarm optimization and trust region framework (TRF).FindingsAmong the primary optimization algorithms, the TRF algorithm met the defined objectives most effectively. The achieved antenna efficiency values exceeded 60.81% in the low band and 68.39% in the high band, along with perfect coverage of the desired bands, demonstrating the success of the design with the TRF algorithm. In addition, the potential electromagnetic field exposure caused by the designed m-MIMO antenna array is elaborated upon in detail using computational human models through specific absorption rate analysis.Originality/valueThe comparison of four different algorithms (two local and two global) for use in the design of a 10-element m-MIMO antenna array with a complex structural configuration and the success of the design implemented with the selected algorithm distinguish this study from others.

Combined Shark-Fin Rooftop Antenna for LTE, WLAN and BeiDou Applications

This paper presents rooftop automobile antennas designed for Long-Term Evolution (LTE), Wireless Local Area Network (WLAN) and navigation system applications. The proposed antennas are housed within a shark-fin structure on the car’s roof, and comprise a main antenna and a diversity antenna. The main antenna and diversity antenna combine for spatial diversity, receiving and processing the same signal to optimize signal quality. To accommodate the limited space within the shark-fin housing, various miniaturization and multiband techniques are utilized. The hexagonal substrate is more closely fitted to the shape of the shark fin, thus making full use of the space of the shark-fin shell. The main antenna and the diversity antenna are perpendicular to each other, which saves the space of the overall antenna and improves the utilization rate of the overall antenna space. The proposed main antenna, compactly sized at 50 mm × 20 mm × 1.59 mm, maintains a VSWR value below 2 across the frequency range of 1.19–2.8 GHz, enabling support for LTE bands 1, 2, 3, 4, 7, 11, 15, 16, 34, 39, 40, and 41, as well as WLAN 2400 bands. The diversity antenna maintains a VSWR value below 2 across the frequency range of 1.5–2.6 GHz, which can cover BeiDou B1-1, LTE 1, 2, 3, 4, 7, 11, 15, 16, 34, 39, and 40, and WLAN 2400 bands. The main antenna and the diversity antenna both demonstrate favorable radiation patterns on the azimuth plane. Simulation and measurement results exhibit a high level of agreement.

Self-isolated MIMO antenna using mixed coupling by close coupling technique

A self-isolated multiple-input-multiple-output (MIMO) antenna in a compact shared ground structure is proposed for 5G systems. The proposed MIMO antenna consists of customized M-pattern, closely coupled members. It benefits to attain good isolation of the targeted bandwidth transversely without additional de-coupling structures. It is discovered that the arm of M-pattern antenna members can cancel out the coupling on the system and achieve sound isolation among antenna members. A relevant matching circuit model is discussed to show how the suggested theory works in principle. The mixed couplings among antenna members neutralize by modifying the antenna shape with the help of electric and magnetic coupling and surface currents. The proposed self-isolated 2-member MIMO antenna demonstrates sound isolation superior to 15 dB transversely in the frequency bands dedicated to 5G NR: n48/n78 and long-term evolution (LTE) band 42/43/48/52 (3.2–3.98 GHz). Moreover, the proposed 2-member design structure has a scalability advantage. It is extended into an 8-members structure, where a pair of antennas located at each side of the frame offers orthogonality. The proposed 8-members M-pattern MIMO is validated using fabricated and simulated measurements. The investigational results show that the 8-members MIMO (M-shaped) system is effective in higher order MIMO antenna design and offers more than 20 dB isolation transversely in the frequency band 5G NR n48 and LTE band 42/43/52(3.29–3.66 GHz).

A Compact and Wideband Dashboard Antenna for Vehicular LTE/5G Wireless Communications

A wideband, low-profile, 3D automotive antenna for Long-Term Evolution (LTE) and 5G applications is presented in this paper. Different from other cellular antennas typically placed under the shark-fin cover or inside a car’s plastic spoiler, the proposed antenna is designed to be integrated inside the vehicle’s dashboard. The 35.5 × 40 × 45 mm3 antenna is compact, lightweight and robust. At the same time, this antenna is capable of operating from 670 up to 5000 MHz, covering the entire LTE/5G band (overall fractional bandwidth of 198%). A shunt stub was introduced between the monopole and ground plane to achieve a low LTE band and provide mechanical robustness for the proposed structure. Simulated performance in terms of reflection coefficient, radiation pattern and realized gain is described, showing a good agreement with the measurement results. Specifically, the antenna has a gain higher than −1 dBi at the low-frequency band (i.e., below 1 GHz) and higher than 3 dBi at the upper-frequency band (i.e., above 1.7 GHz). As per requirements, the ground plane size and layout can be properly chosen to fit the antenna into the available volume as well as to optimize the antenna’s performance.

Designing of Single Band Four Antenna Array for 5G Mobile Applications using MISO Technique

In 5G applications, this paper proposes a single-band four-antenna array for faster velocity and single output (MISO) mechanisms. There were also separate based on step-impedance resonators, L-shaped slot antennas in the established MISO antenna array stepped impedance resonator (SIRs). By calculating the SIR's impedance ratio, the proper single-resonance can be obtained, and for each component in the antenna. By tuning the alignment of the antenna's micro strip antenna app, good impedance matching can be assumed. A decided return loss of more than 10 dB and a measured inter-element isolation of greater than 10.2 dB are illustrated by the experimental results were obtained over the long-term evolution (LTE) band 52 (3358-3640 MHz) and LTE band 20 20 with a simulated cost efficiency of well over 61 percent for each antenna line (5250-5985 MHz). Besides that, between arbitrary two antenna pieces, the decided envelope correlation the coefficient (ECC) is higher than 0.2, and the proposed MISO antenna array achieves a simulated channel capacity of more than 42.5 bps/Hz within both transmission bands. Absolute anthropomorphic mannequins (SAM) in the head and human brain in the presence of, in particular, the MISO antenna array can ensure adequate radiation and MISO accuracy.

Interference mitigation with spectrum sharing and aggregation for SDN based cognitive networks

The Cognitive Radio based Software Defined Network (CR-SDN) integrated with 5G technology provides a promising solution for improving wireless broadband coverage. Cognitive radio technology allows users to communicate with an unlicensed spectrum when it is empty. The proposed Cognitive Radio based Software Defined Networking architecture (CR-SDN) allows Wireless Fidelity (Wi-Fi) and Long Term Evolution (LTE) users to access the Television White Space (TVWS) network whenever there is no vacant band available in Wi-Fi and LTE networks. Wi-Fi and there is a possibility whenever the LTE band interference between two users communicating in the same frequency band simultaneously. This interference should be mitigated, and the spectrum should be shared efficiently among the available users. In this paper, the proposed Interference Mitigation with Spectrum Sharing and Aggregation (IMSSA) technique mitigates the interference and shares the spectrum effectively among licensed and unlicensed users. This technique also aggregates the vacant spectrum within the licensed band (TV band and LTE band) and shares the aggregated band among LTE and Wi-Fi users for achieving a higher data rate. Adaptive Q Learning also made based on the spectrum management adaptive spectrum management, spectrum and a frequency band selection scheme used include dynamic access. This offers high spectrum efficiency and aggregation efficiency for ensuring network performance. The mobility management framework which is adopted in the proposed algorithm undertakes an efficient handover process whenever link failure occurs. In this proposed method, to evaluate the performance following parameter there are transmission rate, primary user analysis and transmission power.

10 Element Sub-6-GHz Multi-Band Double-T Based MIMO Antenna System for 5G Smartphones

A 10 element multiple input multi output (MIMO)/Diversity antenna system is considered to work in Sub-6 GHz frequency range. The proposed design can work in long term evolution (LTE) band 42(3.4-3.6 GHz), LTE band 43(3.6-3.8 GHz) and LTE band 46(5.15-5.925 GHz). The proposed design consists of 10 identical and highly isolated T-shaped slot antennas fed with T-shaped lines. All three bands have the return loss values (<-6 dB) and total antenna efficiency (>83%) in free space. The peak value of envelope correlation coefficient is 0.06 and the calculated value of ergodic channel capacity is found to be greater than 41bps/Hz in all the bands.The effect of hand grip as well as the presence of battery and LCD screen is investigated. Simulated results are validated via fabrication and measurement of the proposed design.

18 Element Massive MIMO/Diversity 5G Smartphones Antenna Design for Sub-6 GHz LTE Bands 42/43 Applications

This work presents an 18 element antenna system compatible with massive multiple input multiple output (MIMO)/Diversity fourth/fifth generation (4G/5G) smartphones. The antennas are designed at sub-6 GHz long term evolution (LTE) band 42 (3.4-3.6 GHz) and LTE band 43 (3.6-3.8 GHz). A simple slot type antenna is considered as the radiating element, with open ended slots used for obtaining a compact design. These slots also act as decoupling elements to improve the isolation among different radiators. The proposed antenna elements are designed on a low-cost FR-4 substrate having dimension of 150 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times80$ </tex-math></inline-formula> mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times1.6$ </tex-math></inline-formula> mm, which can be typically used for 6-inch smart phones. The simulated and measured values of antenna gain are found to be greater than 5.3 dBi. Simulated and measured results of the proposed design show excellent impedance matching (reflection coefficient>20 dB), port isolation (>20 dB), total efficiency (>87%) and Envelope Correlation Coefficient (< 0.01) over the operating frequency. MIMO antenna performance metrics are verified by calculating the ergodic channel capacity with Kronecker channel model.

Reliability Study of Miniaturized Surface Acoustic Wave RF-Filters With Copper Pillar Bump Interconnections

Microacoustic radio frequency filters are essential electronic components for all devices using wireless communication. For miniaturization and cost reduction it is necessary to further reduce the area for the electrical contacts on the chip. CPB (copper pillar bump) interconnections on radio frequency filters can release valuable chip design area of up to 26 % compared to standard SB (solder bump) interconnections on a Qualcomm TFAP (Thin Film Acoustic Package). We developed a process to deposit CPB interconnections on microacoustic radio frequency filters. A 1.20 mm $\times1.60$ mm SAW (surface acoustic wave) LTE (Long Term Evolution) band 26 duplexer with a height of 0.20 mm including the CPB interconnections was investigated. Unbiased highly accelerated stress test, damp heat steady state, dry heat, and temperature cycling reliability tests have shown that the new interconnection technology fulfills the reliability requirements of the smart device industry. Two failure modes caused by extended temperature cycling were identified via scanning acoustic microscopy and scanning electron microscopy analyses on cross sections.

A Low-Profile Wideband Antenna With Monopolelike Radiation Characteristics for 4G/5G Indoor Micro Base Station Application

A wideband, low-profile, vertically polarized antenna with monopolelike radiation characteristics is proposed for 4G/5G indoor base station applications. The design of this antenna is based on the traditional monocone antenna with internal matching and reactive load. The structure of monocone is realized by crossed substrate, which reduces the antenna weight and improves the design flexibility simultaneously. Then, reactive loading of capacitively coupled triangle patches and shorting pins are used to reduce the height of antenna profile to 0.08 λ min, where λ min is the free-space wavelength at the lowest operation frequency. An interdigital capacitor is etched near the antenna's input to adjust the impedance matching. The proposed antenna demonstrates consistent monopolelike, omnidirectional radiation patterns within the operating band. A measured impedance bandwidth for voltage standing-wave ratio (VSWR) < 2.2 of about 81% ranging from 1.66 to 3.95 GHz is achieved, which covers 1.7–2.7 GHz 4G Long-Term Evolution band and 3.3–3.8 GHz 5G N78 band simultaneously. The proposed antenna is tailored for the ceiling micro base station in indoor distributed system.

A multi-slotted antenna for LTE/5G Sub-6 GHz wireless communication applications

AbstractThis paper presents a low-profile multi-slotted patch antenna for long term evolution (LTE) and fifth-generation (5G) communication applications. The studied antenna comprised of a stepped patch and a ground plane. To attain the required operating band, three slots have been inserted within the patch. The insertion of the slots enhances the capacitive effect and helps the prototype antenna to achieve an operating band ranging from 3.15 to 5.55 GHz (S11 ≤−10 dB), covering the N77/N78/N79 for sub-6 GHz 5G wireless communications and LTE bands of 22/42/43/46. The wideband antenna presented in this paper offers omnidirectional stable radiation patterns, good gains, and efficiency with a compact size which make this design an ideal contender for wireless fidelity (WiFi), wireless local area network (WLAN), LTE, and sub-6 GHz 5G communication applications.

Design of MIMO antenna system operating in wideband of 3300 to 6400 MHz for future 5G mobile terminal applications

In this paper, a wideband eight‐element antenna array operating in the 5G (Fifth‐generation) NR (New Radio) frequency bands N77/N78/N79 (3300‐5000 MHz), LTE (Long Term Evolution) band 46 (5150‐5925 MHz), and EU (European Union) 5G band of 5900 to 6400 MHz for 8 × 8 MIMO (Multi‐Input Multi‐Output) operation in the future 5G mobile terminal is presented. The proposed eight antenna elements are all co‐coupled‐fed IFA (Inverted‐F antenna)/loop structure, and are divided into two same sub‐arrays which printed on the inner surface of two long frames of the mobile terminal, respectively. All the simulated and measured results present consecutive 6‐dB impedance bandwidth of 3200 to 6500 MHz, acceptable isolations (better than 12 dB), and good total efficiencies (more than 50%). Besides, the proposed wideband 8‐antenna MIMO system has also shown good MIMO performances with ECCs (envelope correlation coefficient) are all lower than 0.08, and ergodic channel capacities are all higher than 37.8 bps/Hz within the entire desired operation bands. In addition, the hand phantom effects are also investigated. The prototype of the proposed wideband eight‐element antenna array is fabricated and measured, and a quite good agreement between simulation and measurement is obtained.

Designing and performance evaluation of metamaterial inspired antenna for 4G and 5G applications

ABSTRACT A wideband antenna design with double negative metamaterial (DNG) has been designed and evaluated for 4 G and 5 G applications. The antenna design is investigated for wideband operations for 5 G NR (New Radio) n78 band and TDD LTE (Long Term Evolution) bands from LTE band no. 33 to 43. The design is ruled out for size miniaturisation and wide bandwidth using a radiating-folded dipole. The radiating elements can be tuned to adapt to different configurations using controlling parameters. Moreover, the antenna designed is also investigated for SAR, gain, polarisation and efficiency using metamaterial integration. CST microwave studio is used for designing and analysis of the design and the results are validated for the fabricated prototype. The measured and simulated results are in good agreement with each other and proofs to be a good design for 4 G and 5 G communications.

Low cost 3D tin sheet multiband shark‐fin antenna for LTE MIMO vehicular application

AbstractA low cost and low‐profile multiband 3D antenna for roof‐top vehicular applications is presented. The radiating element is obtained through a folded metal sheet shaping a geometry that makes the antenna works in the LTE (Long‐Term Evolution) bands. Thanks to its particular shape and its small size the antenna can be positioned under the automotive common used shark‐fin case. Furthermore, the design allows an easy industrialization process, using low cost material. In fact, the designed shape needs only to be cut and folded without any welding process. In addition to the designed antenna, simulations and measurements take into account another radiating element in order to analyze its behavior in a MIMO (Multiple‐Input‐Multiple‐Output) configuration. For the proposed solution good performances have been demonstrated from both numerical and measurements results.

Wide‐bandwidth inverted‐F stub fed hybrid loop antenna for 5G sub‐6 GHz massive MIMO enabled handsets

A ten-element multi-antenna terminal for massive multiple-input–multiple-output (MIMO) in the fifth-generation (5G) sub-6 GHz with wide impedance bandwidth (IBW) is proposed. A grounded coplanar waveguide is employed to feed an inverted-F stub coupled to a hybrid loop antenna element. Through tuning, the multiple resonant modes are combined so that a wide IBW is achieved. Antenna element sites are selected along the periphery of the typical smartphone back plane of size . To improve the diversity performance, two elements are placed along the horizontal edge orthogonal to the rest of elements placed along the vertical side. The prototype of the antenna is fabricated and measured exhibiting a wide IBW of ( dB) 63% centred around 4.68 GHz. The minimum measured isolation achieved is 18 dB. The maximum simulated envelope correlation coefficient is found to be 0.21 and while the minimum antenna efficiency is 78.4%. Each element has a form factor of and printed on a 1.52 mm thick Rogers 4003 substrate with and . The proposed multi-antenna terminal is suitable for 5G sub-6 GHz (3.2–6.1 GHz) communication including long-term evolution bands 42, 43 and 46.

A Low-Profile Wideband Antenna for WWAN/LTE Applications

In this paper, a low-profile antenna is presented for wideband communication applications. The presented design consists of an I-shaped driven strip and a rectangular ground strip with an open slot in the middle and a steeped lower portion. The measured results demonstrate that the achieved operating band of the proposed antenna has the potential to cover Globalstar satellite phones (GSSP) (1.61–1.63 GHz, uplink), advanced wireless systems (1.71–1.76 GHz, 2.11–2.17 GHz), DCS (1710–1880 MHz), GSM (1800MHz), DCP (1.88–1.90 GHz), DCS-1900/PCS/PHS (1850–1990MHz), WCDMA/IMT-2000 (1920–2170MHz), UMTS (1920–2170 MHz) and long-term evolution (LTE) bands (FDD LTE bands 1–4, 9–10, 15–16, 23–25, 33–37, 39). The designed antenna possessed a very small size of 0.35λ0 × 0.027λ0 at the lowest frequency (S11 ≤ −10dB), achieved good gains and exhibited stable radiation patterns, which makes it suitable for handheld communication devices.

Broadband and Ultrathin Metamaterial Absorber Fabricated on a Flexible Substrate in the Long-Term Evolution Band

In the low-frequency regime, we demonstrated an efficient broadband metamaterial absorber (MA) by integrating an active low-conductivity ground plate into the common sandwiched structure. The energy of every electromagnetic (EM) wave radiated from the ultrahigh frequency to the long-term evolution band is trapped inside an ultrathin/flexible MA, which has a thickness of only λ/1362 at the lowest working wavelength. This performance of proposed MA in the defined band is also predicted through a simplified equivalent-circuit model and the simulation. Correspondingly, our MA absorbs over 90% in the wide band from 0.2 GHz to 3.6 GHz (fractional bandwidth of 179.0%). In particular, this MA also exhibits the stable features of omni-directionality (incident angle up to 40°) and polarization independence of the EM waves. Our innovation offers a different approach to realize the potential wearable smart meta-devices by using these ultrathin broadband MAs.

Efficient Resource Allocation for IoT Cellular Networks in the Presence of Inter-Band Interference

An Internet-of-Things (IoT) cellular network is considered in which IoT devices communicate with an IoT base station using IoT sub-bands placed between long-term evolution (LTE) bands. Due to spectral leakage, inter-band interference exists among IoT sub-bands and also between LTE and IoT bands. It is assumed that the IoT cellular network is responsible for reducing its interference to the LTE network to a certain threshold level. Under such interference regulation to LTE bands, we establish a joint sub-band assignment and power allocation optimization in order to maximize the sum rate of the IoT cellular network. A novel two-stage suboptimal algorithm that sequentially performs sub-band assignment and power control is proposed, reflecting the impact of spectral leakage in its optimization procedure. Simulation results demonstrate that the proposed algorithm considering the impact of spectral leakage outperforms the conventional optimization algorithms without considering spectral leakage. It is further shown that it provides almost the same sum rate achievable for a stand-alone network as if there were no LTE networks.