scholarly journals Low-Cost Automated Design of Compact Branch-Line Couplers

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3562
Author(s):  
Adrian Bekasiewicz
Keyword(s):  
Communication Systems ◽  
State Of The Art ◽  
Low Cost ◽  
Trust Region ◽  
Automated Design ◽  
Alternative Methods ◽  
Design Parameters ◽  
Wireless Communication Systems ◽  
Branch Line ◽  
Power Split

Branch-line couplers (BLCs) are important components of wireless communication systems. Conventional BLCs are often characterized by large footprints which make miniaturization an important pre-requisite for their application in modern devices. State-of-the-art approaches to design compact BLCs are largely based on the use of high-permittivity substrates and multi-layer topologies. Alternative methods involve replacement of transmission-line sections of the circuit, with their composite counterparts, referred to as compact cells (CCs). Due to the efficient use of available space, CC-based couplers are often characterized by small footprints. The design of compact BLCs is normally conducted based on engineering experience. The process is laborious and requires many adjustments of topology followed by manual or, semi-automatic tuning of design parameters. In this work, a framework for low-cost automated design of compact BLCs using pre-defined CCs is proposed. The low cost of the presented design technique is ensured using equivalent-circuit models, space mapping correction methods, and trust-region-based local optimization algorithms. The performance of the framework is demonstrated based on three examples, concerning the design of unequal-power split coupler, comparison of automatically generated compact BLCs, as well as rapid re-design of the coupler for different substrates. Furthermore, the approach has been benchmarked against the state-of-the-art methods for low-cost design of circuits.

scholarly journals Intelligent Reflective Surfaces for Wireless Networks: An Overview of Applications, Approached Issues, and Open Problems

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2345
Author(s):  
Darian Pérez-Adán ◽  
Óscar Fresnedo ◽  
José P. González-Coma ◽  
Luis Castedo
Keyword(s):  
Communication Technology ◽  
Communication Systems ◽  
Performance Metrics ◽  
State Of The Art ◽  
Low Cost ◽  
Future Research ◽  
Wireless Communication Systems ◽  
Open Problems ◽  
Literature Overview ◽  
Massive Number

An intelligent reflective surface (IRS) is a novel and revolutionizing communication technology destined to enable the control of the radio environment. An IRS is a real-time controllable reflectarray with a massive number of low-cost passive elements which introduce a phase shift to the incoming signals from the sources before the propagation towards the destination. This technology introduces the notion of a smart propagation environment with the aim of improving the system performance. In this paper, we provide a comprehensive literature overview on IRS technology, including its basic concepts and reconfiguration, as well as its design aspects and applications for wireless communication systems. We also study the performance metrics and the setups considered in recent publications related to IRS and provide suggestions of future research lines based on still unexplored use cases in the state-of-the-art.

scholarly journals Physical-Layer Security Improvement with Reconfigurable Intelligent Surfaces for 6G Wireless Communication Systems

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1439
Author(s):  
Janghyuk Youn ◽  
Woong Son ◽  
Bang Chul Jung
Keyword(s):  
Wireless Communication ◽  
Physical Layer Security ◽  
Communication Systems ◽  
Low Cost ◽  
Physical Layer ◽  
Base Station ◽  
Wireless Communication Systems ◽  
Secrecy Rate ◽  
Pilot Signal ◽  
Time Division

Recently, reconfigurable intelligent surfaces (RISs) have received much interest from both academia and industry due to their flexibility and cost-effectiveness in adjusting the phase and amplitude of wireless signals with low-cost passive reflecting elements. In particular, many RIS-aided techniques have been proposed to improve both data rate and energy efficiency for 6G wireless communication systems. In this paper, we propose a novel RIS-based channel randomization (RCR) technique for improving physical-layer security (PLS) for a time-division duplex (TDD) downlink cellular wire-tap network which consists of a single base station (BS) with multiple antennas, multiple legitimate pieces of user equipment (UE), multiple eavesdroppers (EVEs), and multiple RISs. We assume that only a line-of-sight (LOS) channel exists among the BS, the RISs, and the UE due to propagation characteristics of tera-hertz (THz) spectrum bands that may be used in 6G wireless communication systems. In the proposed technique, each RIS first pseudo-randomly generates multiple reflection matrices and utilizes them for both pilot signal duration (PSD) in uplink and data transmission duration (DTD) in downlink. Then, the BS estimates wireless channels of UE with reflection matrices of all RISs and selects the UE that has the best secrecy rate for each reflection matrix generated. It is shown herein that the proposed technique outperforms the conventional techniques in terms of achievable secrecy rates.

scholarly journals A 300-GHz low-cost high-gain fully metallic Fabry–Perot cavity antenna for 6G terahertz wireless communications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basem Aqlan ◽  
Mohamed Himdi ◽  
Hamsakutty Vettikalladi ◽  
Laurent Le-Coq
Keyword(s):  
Communication Systems ◽  
Low Cost ◽  
Frequency Selective Surface ◽  
High Gain ◽  
Wireless Communication Systems ◽  
Beam Radiation ◽  
Compact Size ◽  
Fabry Perot ◽  
Operating Bandwidth ◽  
Polarization Level

AbstractA low-cost, compact, and high gain Fabry–Perot cavity (FPC) antenna which operates at 300 GHz is presented. The antenna is fabricated using laser-cutting brass technology. The proposed antenna consists of seven metallic layers; a ground layer, an integrated stepped horn element (three-layers), a coupling layer, a cavity layer, and an aperture-frequency selective surface (FSS) layer. The proposed aperture-FSS function acts as a partially reflective surface, contributing to a directive beam radiation. For verification, the proposed sub-terahertz (THz) FPC antenna prototype was developed, fabricated, and measured. The proposed antenna has a measured reflection coefficient below − 10 dB from 282 to 304 GHz with a bandwidth of 22 GHz. The maximum measured gain observed is 17.7 dBi at 289 GHz, and the gain is higher than 14.4 dBi from 285 to 310 GHz. The measured radiation pattern shows a highly directive pattern with a cross-polarization level below − 25 dB over the whole band in all cut planes, which confirms with the simulation results. The proposed antenna has a compact size, low fabrication cost, high gain, and wide operating bandwidth. The total height of the antenna is 1.24 $${\lambda }_{0}$$ λ 0 ($${\lambda }_{0}$$ λ 0 at the design frequency, 300 GHz) , with a size of 2.6 mm × 2.6 mm. The proposed sub-THz waveguide-fed FPC antenna is suitable for 6G wireless communication systems.

Reconfigurable Antenna

2016 ◽  
pp. 237-263
Author(s):  
Mohamad Kamal A Rahim ◽  
Huda A. A. Majid ◽  
Mohamad Rijal Hamid
Keyword(s):  
Communication Systems ◽  
Low Cost ◽  
Wireless Systems ◽  
Reconfigurable Antennas ◽  
Effective Length ◽  
Slot Antenna ◽  
Wireless Communication Systems ◽  
Reconfigurable Antenna ◽  
5 Ghz ◽  
Narrow Bands

Reconfigurable antennas have attracted a lot of attention especially in future wireless communication systems. Superior features such as reconfigurable capability, low cost, multi-purpose functions and size miniaturization have given reconfigurable antennas advantage to be integrated into a wireless systems. In this chapter, two types of reconfigurable antennas are discussed. First, frequency reconfigurable narrowband microstrip slot antenna (FRSA) is presented. The proposed antenna is designed to operate at six reconfigurable frequency bands from 2 GHz to 5 GHz with bidirectional radiation pattern. The second antenna design is frequency reconfigurable narrowband patch-slot antenna (FRPSA) is presented. The antenna is a combination of a microstrip patch and slot antenna. Nine different narrow bands are produced by tuning the effective length of the slot. The performances of the antenna in term of simulated and measured results are presented. In conclusion, good agreement between the simulated and measured results has been attained.

scholarly journals PRECISION AND ACCURACY PARAMETERS IN STRUCTURED LIGHT 3-D SCANNING

2016 ◽  
Vol XL-5/W8 ◽  
pp. 7-15 ◽  
Author(s):  
E. R. Eiríksson ◽  
J. Wilm ◽  
D. B. Pedersen ◽  
H. Aanæs
Keyword(s):  
State Of The Art ◽  
Low Cost ◽  
Structured Light ◽  
Quantitative Measure ◽  
Calibration Procedure ◽  
Design Parameters ◽  
Precision And Accuracy ◽  
Structured Light Systems ◽  
Encoding Strategy ◽  
Cost Components

Structured light systems are popular in part because they can be constructed from off-the-shelf low cost components. In this paper we quantitatively show how common design parameters affect precision and accuracy in such systems, supplying a much needed guide for practitioners. Our quantitative measure is the established VDI/VDE 2634 (Part 2) guideline using precision made calibration artifacts. Experiments are performed on our own structured light setup, consisting of two cameras and a projector. We place our focus on the influence of calibration design parameters, the calibration procedure and encoding strategy and present our findings. Finally, we compare our setup to a state of the art metrology grade commercial scanner. Our results show that comparable, and in some cases better, results can be obtained using the parameter settings determined in this study.

scholarly journals Liquid-Based Reconfigurable Antenna Technology: Recent Developments, Challenges and Future

2020 ◽  
Author(s):  
Habshah Abu Bakar ◽  
Rosemizi Abd Rahim ◽  
Ping Jack Soh ◽  
Prayoot Akkaraekthalin
Keyword(s):  
High Frequency ◽  
Communication Systems ◽  
Room Temperature ◽  
State Of The Art ◽  
Reconfigurable Antennas ◽  
Wireless Communication Systems ◽  
Dielectric Resonators ◽  
Different Types ◽  
Recent Developments ◽  
Basic Approaches

Advances in reconfigurable liquid-based reconfigurable antennas are enabling new possibilities to fulfil the requirements of more advanced wireless communication systems. In this review, a comparative analysis of various state-of-the-art concepts and techniques for designing reconfigurable antennas using liquid is presented. First, the electrical properties of different liquids at room temperature commonly used in reconfigurable antennas are identified. This is followed by a discussion of various liquid actuation techniques in enabling high frequency reconfigurability. Next, liquid-based reconfigurable antennas in literature used to achieve the different types of reconfiguration will be critically reviewed. These include frequency-, polarization-, radiation pattern- and compound reconfigurability. The current concepts of liquid-based reconfigurable antennas can be classified broadly into three basic approaches: altering the physical (and electrical) dimensions of antennas using liquid, applying liquid-based sections as reactive loads; and implementation of liquids as dielectric resonators. Each concept and their design approaches will be examined, outlining their benefits, limitations, and possible future improvements.

scholarly journals Liquid-Based Reconfigurable Antenna Technology: Recent Developments, Challenges and Future

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 827
Author(s):  
Habshah Abu Bakar ◽  
Rosemizi Abd Rahim ◽  
Ping Jack Soh ◽  
Prayoot Akkaraekthalin
Keyword(s):  
High Frequency ◽  
Communication Systems ◽  
Room Temperature ◽  
State Of The Art ◽  
Reconfigurable Antennas ◽  
Wireless Communication Systems ◽  
Dielectric Resonators ◽  
Different Types ◽  
Recent Developments ◽  
Basic Approaches

Advances in reconfigurable liquid-based reconfigurable antennas are enabling new possibilities to fulfil the requirements of more advanced wireless communication systems. In this review, a comparative analysis of various state-of-the-art concepts and techniques for designing reconfigurable antennas using liquid is presented. First, the electrical properties of different liquids at room temperature commonly used in reconfigurable antennas are identified. This is followed by a discussion of various liquid actuation techniques in enabling high frequency reconfigurability. Next, the liquid-based reconfigurable antennas in literature used to achieve the different types of reconfiguration will be critically reviewed. These include frequency-, polarization-, radiation pattern-, and compound reconfigurability. The current concepts of liquid-based reconfigurable antennas can be classified broadly into three basic approaches: altering the physical (and electrical) dimensions of antennas using liquid; applying liquid-based sections as reactive loads; implementation of liquids as dielectric resonators. Each concept and their design approaches will be examined, outlining their benefits, limitations, and possible future improvements.

scholarly journals Implementation of Multiband Communication Using SDR for Remote Application

2020 ◽  
Author(s):  
Madhuri Gummineni ◽  
Trinatha Rao Polipalli
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Low Cost ◽  
Wireless Communication Systems ◽  
Simulation Based ◽  
End To End ◽  
To Come ◽  
Multimode Operation ◽  
Reconfigurable Radio ◽  
Multi Mode

Abstract To develop Next Generation Wireless Communication a generic hardware design is required so that it can be driven by software to allow for future upgrades. Thus Reconfigurable Radio implements multi-band, multi-mode operation and interoperability with low-cost. For reducing response time between incompatible radios during emergencies interoperability is essential for a secure heterogeneous communication. Some of the Challenges identified for implementing reliable and reconfigurable wireless communication systems are: specific training required for using the equipment, end-to-end connectivity between devices, extending link capacity during the high peak utilization. Each device and architecture will differ based on the type of communication system. Interconnecting emerging fields enhances the performance , implementation helps to come across alternatives to overcome practical difficulties and challenges of connecting different fields to Cognitive Radio(CR). Earlier research gave prominence to theoretical and simulation-based work. This motivates us to verify interoperability in real time using SDR. This paper describes the implementation of a Multiband, multimode operation for establishing communication between different types of architecture i.e. VUSDR (HAM), Hack RF One, LoRa, RF module, GSM module and USRP N210 to prove reliability and end-to-end communication.

scholarly journals Machine Learning in Beyond 5G/6G Networks—State-of-the-Art and Future Trends

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2786
Author(s):  
Vasileios P. Rekkas ◽  
Sotirios Sotiroudis ◽  
Panagiotis Sarigiannidis ◽  
Shaohua Wan ◽  
George K. Karagiannidis ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Machine Learning ◽  
Wireless Communications ◽  
Wireless Communication ◽  
Communication Systems ◽  
State Of The Art ◽  
Wireless Communication Systems ◽  
Future Trends ◽  
Network Applications ◽  
Open Issues

Artificial Intelligence (AI) and especially Machine Learning (ML) can play a very important role in realizing and optimizing 6G network applications. In this paper, we present a brief summary of ML methods, as well as an up-to-date review of ML approaches in 6G wireless communication systems. These methods include supervised, unsupervised and reinforcement techniques. Additionally, we discuss open issues in the field of ML for 6G networks and wireless communications in general, as well as some potential future trends to motivate further research into this area.

Sign in / Sign up

Export Citation Format

Share Document