scholarly journals Two-Step Method for Millimeter-Wave Antenna Performance Assessment in 5G Smartphones

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Filipa S. S. Fernandes ◽  
Christian Rom ◽  
António Rodrigues ◽  
Simon Svendsen ◽  
Ole Jagielski
Keyword(s):  
Form Factor ◽  
Beam Steering ◽  
Wave Spectrum ◽  
Path Loss ◽  
Mimo Channel ◽  
Paradigm Shifts ◽  
Step Method ◽  
Implementation Challenges ◽  
Antenna Performance ◽  
User Influence

A critical challenge for 5G is transitioning to the mm-Wave spectrum. Despite providing unprecedented data rates, mm-Waves also suffer high path loss, atmospheric absorption, and higher fluctuating channel conditions, sparking numerous paradigm shifts in the smartphone industry. Extending mm-Wave communications to smartphones requires first a comprehensive study to identify the antenna design/smartphone implementation challenges that impact the quality of communications. This work proposes a two-step assessment metric, the mmWAESI, to evaluate mm-Wave antennas’ potential and limitations regarding their impact on system performance. First, it analyzes the spatial distribution of the smartphone-integrated beam steering array’s radiated power. Then, it evaluates the antenna’s influence on the MIMO performance, using a discrete, time-variant geometrical MIMO channel simulator to recreate any mm-Wave propagation scenario. For enhanced accuracy, mmWAESI accounts simultaneously for several communication aspects: antenna type, realistic radiation patterns, mobile phone form factor constraints, phone orientation, and user influence. The method is illustrated for two different 4-element linear arrays at 39 GHz, based on patch or monopole elements, integrated into smartphones. Their performance is compared under similar conditions, revealing that, unless array switching is employed, the smartphone’s form factor and user influence will mask any potential advantage of the unperturbed array characteristics.

scholarly journals Conceiving Inferential Prototypes of MIMO Channel Models via Buckingham’s Similitude Principle for 30+ GHz through THz Spectrum

2021 ◽  
Vol 9 (3) ◽  
pp. 1-35
Author(s):  
Perambur Neelakanta ◽  
Dolores De Groff
Keyword(s):  
Multiple Input Multiple Output ◽  
Path Loss ◽  
Spatial Multiplexing ◽  
Mimo Channel ◽  
Channel Models ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Channel Statistics ◽  
Wave Range ◽  
Test Spectrum

Facilitating newer bands of ‘unused’ segments (windows) of RF spectrum falling in the mm-wave range (above 30+ GHz) and seeking usable stretches across unallocated THz spectrum, could viably be considered for Multiple Input Multiple Output (MIMO) communications. This could accommodate the growing needs of multigigabit 3G/4G applications in outdoor-based backhauls in picocellular networks and in indoor-specific multimedia networking. However, in contrast with cellular and Wi-Fi, wireless systems supporting sub-mm wavelength transreceive communications in the outdoor electromagnetic (EM) ambient could face “drastically different propagation geometry”; also, in indoor contexts, envisaging pertinent spatial-multiplexing with directional, MIMO links could pose grossly diverse propagation geometry across a number of multipaths; as such, channel-models based on stochastic features of diverse MIMO-specific links in the desired test spectrum of mm-wave/THz band are sparsely known and almost non-existent. To alleviate this niche, a method is proposed here to infer sub-mm band MIMO channel-models (termed as “prototypes”) by judiciously sharing “similarity” of details available already pertinent to traditional “models” of lower-side EM spectrum, (namely, VLF through micro-/mm-wave). Relevant method proposed here relies on the “principle of similitude” due to Edgar Buckingham. Exemplar set of “model-to-(inferential)-prototype” transformations are derived and prescribed for an exhaustive set of fading channel models as well as, towards estimating path-loss of various channel statistics in the high-end test spectrum.

scholarly journals A Comparative Study of On-Body Radio-Frequency Links in the 420 MHz–2.4 GHz Range

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4165 ◽  
Author(s):  
Arno Thielens ◽  
Robin Benarrouch ◽  
Stijn Wielandt ◽  
Matthew Anderson ◽  
Ali Moin ◽  
...  
Keyword(s):  
Comparative Study ◽  
Radio Frequency ◽  
Phased Array ◽  
Beam Steering ◽  
Path Loss ◽  
Mitigation Strategies ◽  
Body Area ◽  
The Right ◽  
Path Loss Measurements ◽  
Selection Of

While there exists a wide variety of radio frequency (RF) technologies amenable for usage in Wireless Body Area Networks (WBANs), which have been studied separately before, it is currently still unclear how their performance compares in true on-body scenarios. In this paper, a single reference on-body scenario—that is, propagation along the arm—is used to experimentally compare six distinct RF technologies (between 420 MHz and 2.4 GHz) in terms of path loss. To further quantify on-body path loss, measurements for five different on-body scenarios are presented as well. To compensate for the effect of often large path losses, two mitigation strategies to (dynamically) improve on-body links are introduced and experimentally verified: beam steering using a phased array, and usage of on-body RF repeaters. The results of this study can serve as a tool for WBAN designers to aid in the selection of the right RF frequency and technology for their application.

scholarly journals A Miniaturized Butler Matrix Based Switched Beamforming Antenna System in a Two-Layer Hybrid Stackup Substrate for 5G Applications

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1232 ◽  
Author(s):  
Soyeon Kim ◽  
Seongjo Yoon ◽  
Yongho Lee ◽  
Hyunchol Shin
Keyword(s):  
Antenna Array ◽  
Return Loss ◽  
Lower Layer ◽  
Beam Steering ◽  
System Size ◽  
Antenna System ◽  
Wireless Applications ◽  
Butler Matrix ◽  
Antenna Performance ◽  
Circuit Components

This work presents a Butler matrix based four-directional switched beamforming antenna system realized in a two-layer hybrid stackup substrate for 28-GHz mm-Wave 5G wireless applications. The hybrid stackup substrate is composed of two layers with different electrical and thermal properties. It is formed by attaching two layers by using prepreg, in which the circuit components are placed in both outer planes and the ground layers are placed in the middle. The upper layer that is used as antenna substrate has εr = 2.17, tanδ = 0.0009 and h = 0.254 mm. The lower layer that is used as a Butler matrix substrate has εr = 6.15, tanδ = 0.0028 and h = 0.254 mm. By realizing the antenna array on the lower-εr layer while the Butler matrix on the higher-εr layer, the Butler matrix dimension is significantly reduced without sacrificing the array antenna performance, leading to significant overall antenna system size reduction. The two-layer substrate approach also significantly suppresses parasitic radiation leaking from the Butler matrix toward the antenna side, allowing overall radiation pattern improvement. The fabricated beamforming antenna is composed of 1 × 4 patch antenna array and a 4 × 4 Butler matrix. The measured return loss is lower than −8 dB at all ports in 28-GHz. It demonstrates the switched beam steering toward four distinct angles of—16°, +36°, −39°, and +7°, with the sidelobe levels of −12, −11.7, −6, and −13.8 dB, respectively. Antenna gain is found to be about 10 dBi. Due to the two-layer hybrid stackup substrate, the total antenna system is realized only in 1.7λ × 2.1λ, which shows the smallest form factor compared to similar other works.

scholarly journals Subsurface MIMO: A Beamforming Design in Internet of Underground Things for Digital Agriculture Applications

2019 ◽  
Vol 8 (3) ◽  
pp. 41 ◽  
Author(s):  
Abdul Salam
Keyword(s):  
Degrees Of Freedom ◽  
Phased Array ◽  
Beam Steering ◽  
Mimo Channel ◽  
Interference Channel ◽  
Capacity Region ◽  
Phased Array Antenna ◽  
Soil Medium ◽  
Digital Agriculture ◽  
Underground Communications

In underground (UG) multiple-input and multiple-output (MIMO), transmit beamforming is used to focus energy in the desired direction. There are three different paths in the underground soil medium through which the waves propagate to reach the receiver. When the UG receiver receives a desired data stream only from the desired path, then the UG MIMO channel becomes a three-path (lateral, direct, and reflected) interference channel. Accordingly, the capacity region of the UG MIMO three-path interference channel, and the degrees of freedom (multiplexing gain of this MIMO channel) requires careful modeling. Therefore, expressions are required for the degrees of freedom of the UG MIMO interference channel. The underground receiver needs to perfectly cancel the interference from the three different components of the EM waves propagating in the soil medium. This concept is based upon reducing the interference of the undesired components to a minimum level at the UG receiver using the receive beamforming. In this paper, underground environment-aware MIMO using transmit and receive beamforming has been developed. The optimal transmit and receive beamforming, combining vectors under minimal intercomponent interference constraints, are derived. It is shown that UG MIMO performs best when all three components of the wireless UG channel are leveraged for beamforming. The environment-aware UG MIMO technique leads to three-fold performance improvements and paves the way for design and development of next-generation sensor-guided irrigation systems in the field of digital agriculture. Based on the analysis of underground radio-wave propagation in subsurface radio channels, a phased-array antenna design is presented that uses water content information and beam-steering mechanisms to improve efficiency and communication range of wireless underground communications. It is shown that the subsurface beamforming using phased-array antennas improves wireless underground communications by using the array element optimization and soil–air interface refraction adjustment schemes. This design is useful for subsurface communication system where sophisticated sensors and software systems are used as data collection tools that measure, record, and manage spatial and temporal data in the field of digital agriculture.

scholarly journals Ultra-wideband slot-loaded planar antenna for future 5G millimeter wave applications

Tehnika ◽  
2021 ◽  
Vol 76 (5) ◽  
pp. 623-628
Author(s):  
Surendra Gupta ◽  
Amit Bage ◽  
Milka Potrebić ◽  
Lakhindar Murmu
Keyword(s):  
Millimeter Wave ◽  
Ground Plane ◽  
Wave Spectrum ◽  
Ultra Wideband ◽  
Planar Antenna ◽  
Cross Polarization ◽  
Defected Ground Structure ◽  
Antenna Performance ◽  
The Given ◽  
Polarization Level

An ultra-wideband, compact planar antenna with defected ground structure (DGS) has been presented in this article for future 5G millimeter-wave applications. The proposed antenna overcomes the limitation of bandwidth of the conventional microstrip patch antenna (typically < 5%). The antenna exhibits an ultra-wideband characteristic covering frequency band from 21.3 GHz to 40.6 GHz which makes the fractional bandwidth of 62.36%. The antenna performance is enhanced by etching slots on the patch and incorporating defect on the ground plane. The antenna achieves gain greater than 4.01 dBi and radiation efficiency greater than 95% throughout the operating band. In the given band it also exhibits very low cross-polarization level as well as stable radiation performance. This antenna is designed to operate in n257, n258, n260 and n261 5G millimeter-wave spectrum.

scholarly journals Optimization Environment Definition for Beam Steering Reflectarray Antenna Design

Mathematics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 33
Author(s):  
Alessandro Niccolai ◽  
Francesco Grimaccia ◽  
Marco Mussetta ◽  
Riccardo Zich ◽  
Alessandro Gandelli
Keyword(s):  
Beam Steering ◽  
Aerospace Industry ◽  
High Gain ◽  
Antenna Design ◽  
Antenna Performance ◽  
Design Variables ◽  
Low Profile ◽  
Evolutionary Optimization Algorithms ◽  
Reflectarray Antenna ◽  
Complete Optimization

Reflectarray antennas are low-profile high-gain systems widely applied in the aerospace industry. The increase in their application is leading to the problem of getting more advanced performance while keeping the system as simple as possible. In these cases, their design cannot be conducted via analytical methods, thus evolutionary optimization algorithms are often implemented. Indeed, the design is characterized by the presence of many local minima, by high number of design variables, and by the high computational burden required to evaluate the antenna performance. The purpose of this paper is to develop, implement, and test a complete Optimization Environment that can be applied to achieve high scanning capabilities with a reflectarray. The design of the optimization environment has been selected to be flexible enough to be applied also with other different algorithms.

scholarly journals User Influence on MIMO Channel Capacity for Handsets in Data Mode Operation

2012 ◽  
Vol 60 (2) ◽  
pp. 633-643 ◽  
Author(s):  
Jesper Ødum Nielsen ◽  
Boyan Yanakiev ◽  
Ivan B. Bonev ◽  
Morten Christensen ◽  
Gert Frølund Pedersen
Keyword(s):  
Channel Capacity ◽  
Mimo Channel ◽  
Mode Operation ◽  
User Influence ◽  
Mimo Channel Capacity

scholarly journals Investigation of MIMO Channel Characteristics in a Two-Section Tunnel at 1.4725 GHz

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Rongchen Sun ◽  
David W. Matolak ◽  
Cheng Tao ◽  
Liu Liu ◽  
Zhenhui Tan ◽  
...  
Keyword(s):  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Vertical Wall ◽  
Path Loss ◽  
Wide Band ◽  
Singular Values ◽  
Mimo Channel ◽  
Center Frequency ◽  
Delay Spread ◽  
Single Input Single Output

This paper presents results from a wide band single-input–single-output (SISO) and 16 × 16 virtual multiple-input–multiple-output (MIMO) measurement campaign at a center frequency of 1.4725 GHz in a 100-meter long tunnel laboratory which is terminated by a vertical wall with a metallic door. The path loss, root-mean-square delay spread (RMS-DS) characteristics, and power delay profiles (PDPs) are described. In addition, we provide results for the MIMO channel amplitude matrix, which offers a new perspective in understanding MIMO characteristics in tunnel scenarios. Our measurement results are analyzed and compared to ray tracing simulations. The relationships among the angle spread, channel matrix singular values, and MIMO capacity at various link distances are illustrated, and these provide insights into MIMO system deployment.

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