Ultra-wideband Communication Research Articles

Sextuple band rejection functionality from a compact Koch anti-snowflake fractal UWB-MIMO antenna integrated with split-ring resonators and slots

In this article, a dual-port modified Koch Anti-snowflake fractal antenna is designed and experimentally verified for ultra-wideband performance with hexa-band suppression functionality. The designed array occupies a total area of 29.5 × 43.5 mm2. Initially, it consists of two microstrip-fed modified Koch Anti-snowflake fractal (iterated up to 3rd order) patches and a defected ground plane, aimed to achieve 144.6% fractional bandwidth (2.48–15.42 GHz) with optimum isolation characteristics (S21/S12 ≤ -17 dB). The proposed fractal geometry minimizes the patch area by 42.4% as compared to the circular configuration. Further, each fractal patch is embedded with a Z-shaped and inverted L-shaped slit to suppress the unwanted WiMAX (3.3–3.77 GHz) and INSAT (4.57–4.9 GHz) band respectively. Two SRR pairs and a G-shaped slot are loaded in each feedline of the designed array to realize notches at 6.578 GHz (super-extended C-band), 8.23 GHz (ITU-8), and 10.22 GHz (amateur radio) respectively. A pair of L-shaped slits is removed from the reduced ground to eliminate the interfering WLAN (5.18–5.82 GHz) band. Various diversity parameters for the designed array are examined and are found within their permissible levels. The experimental results of the fabricated array (without and with notch elements) present an acceptable resemblance with the simulated ones, therefore assuring the practicability of the designed array in ultrawideband communication systems.

A new insightful exploration into a low profile ultra-wide-band (UWB) microstrip antenna for DS-UWB applications

Designing a simple and planar antenna for high speed short distance ultra-wideband (UWB) communication has become a buzzword over the last few years. There are two very different categories of UWB technologies of vital relevance, i.e. (i) carrier-free direct sequence UWB (DS-UWB), and (ii) the Multi-Band orthogonal frequency division multiplexing UWB (OFDM UWB) technology. In, Multi-Band OFDM UWB technology, multi narrowband UWB antennas with frequency notches are required. However, in DS-UWB technology, the frequency spectrum of very short duration transmitted pulses occupies wide bandwidth, and hence to transmit it, the antenna should be fully matched over the entire bandwidth without the presence of any frequency notch. In this paper, a novel, small and completely planar air gap and defected ground slot integrated rectangular microstrip antenna with dual shorting posts have been thoroughly investigated to yield UWB, i.e. (109%) bandwidth without the presence of any frequency notch.

Compact 4 × 4 Proximity Coupled Microstrip Fed UWB Stepped Slot MIMO Antenna Having Triple Band Rejection

The presented antenna is a novel highly isolated compact four-element Multiple Input Multiple Output (MIMO) antenna with common ground, which can reject three undesired bands effectively for Ultra-Wideband (UWB) Communication. The overlapping of narrowband communication systems with the UWB spectrum makes radio signals interfere. Therefore, the proposed antenna is designed with triple-band rejection capability. The antenna consists of four feedlines and a common ground surface which acts as the main radiator. The four elements of the antenna are kept orthogonally to exploit polarisation diversity, resulting in high isolation. The presented antenna is having size = 44 × 44 mm2 and printed on FR4 substrate. A spiral slot was introduced in the ground surface which behaves similarly as a band-stop filter (BSF) and rejects the X- band for Uplink Satellite Communication. For rejecting WiMAX and WLAN band, the modified trident shape of the microstrip line is used. Also, Defected Ground Structure (DGS) is used for the isolation (> 23 dB) enhancement. Simulation and measurement results are quite similar. The proposed antenna is used for small handheld communication devices.

UWB dual-notched planar antenna by utilizing compact open meander slitted EBG structure

In this paper, an ultra-wideband (UWB) dual-notch planar antenna is presented. The antenna, in its structure, utilizes a compact electromagnetic bandgap (EBG) structure with new open meander slits to notch two frequency bands at around 3.5 and 5.5 GHz. The main idea is to place the new slitted mushroom-type EBG structure at the vicinity of the feedline to achieve filtering ability for the antenna. The presented EBG structure has many benefits, like notched bands with sharp roll off, independent control over the notched bands, little effects on antenna performance, easy switching configuration and reduction of the required number of EBG cells. The fabricated antenna shows −10 dB bandwidth of 2.63 up to 13 GHz with dual-notched in the frequency bands of 3.11–4.01 GHz and 5.15–5.98 GHz. Simulation and experimental results exhibit a close agreement with each other. The proposed UWB antenna with a flat transfer function and a constant group delay at the notched bands is a suitable choice for compact UWB communication systems.

Ultra-wideband ultra-short pulse communication system

Problem statement. The development and design of radio communication systems with enhanced structural and energy stealth properties are of the greatest interest in modern radio engineering. One method of implementing such radio systems is the use of ultra-wideband signals. Despite advances in radio engineering theory, the development and design of ultra-wideband radio systems are at the initial stage. The results obtained in this subject area are not systematized, limiting their practical application and indicating the relevance of the chosen research problem.The study's objective is to formalize an approach to the design and performance assessment of ultra-wideband radio systems based on statistical radio engineering methods. Bringing the obtained theoretical solutions to the level of practical implementation in a radio station layout.Results. The analysis of available theoretical and practical solutions in the subject area of ultra-wideband radio systems is carried out. The principles of development and evaluation taking into account the characteristics of radio equipment elements are justified. A model of an ultra-wideband radio pulse is presented. The requirements of guiding documents are summarized, based on which the requirements for radio equipment are clarified. The criteria for the formation and processing of ultra-wideband signals are determined. An approach to controlling the parameters of the applied signals is considered. The criterion of increasing the efficiency of radio systems is justified. An approach to calculating the size of the pulse packs defining the signal symbols is developed. Analytical calculations are presented following the developed approach.Practical implications. The authors developed a model of an ultra-wideband radio station based on LLC Scientific Production Enterprise "New Telecommunications Technologies". The obtained practical solutions can be used in the field of practical implementation of ultra-wideband radio communication systems

Design and Analysis of a Compact UWB-MIMO Antenna with Improved Isolation for UWB/WLAN Applications

For space limited ultra-wideband (UWB) communication system, the small foot print of the multi-input multi-output (MIMO) antenna is highly desirable. A significant subject of the investigation is the creation of a small MIMO antenna with enhanced isolation and large operating bandwidth. To accomplish this object, a compact size two-port UWB-MIMO antenna is presented in this article. The proposed antenna consists of opposite faced semi-circular monopole radiating elements. The opposite orientation of the radiating elements is offered low envelope correlation coefficient (ECC) and good pattern diversity. The improved bandwidth and enhanced isolation are achieved by etching the ground plane with a rectangular defected ground structure structure. Antenna size optimization is taking placed with evolution of the compact size single UWB antenna element. The computer simulation tool is used to complete the design and optimization process. The optimized size of the proposed antenna is 20 × 20 mm2 or electrical size of 0.469 λ0 × 0.469 λ0. The fabricated prototype of the antenna is experimentally evaluated and validated by the comparison of the simulated and measured results. However, obtained results show well agreement. The proposed antenna has extended UWB bandwidth 2–12 GHz (fractional bandwidth of 142.8%) and improved isolation of less than 25 dB, and low value of ECC (0.05). The antenna size, isolation, operating bandwidth, and ECC are compared with previously reported work. Furthermore, the proposed antenna is preferable for WLAN and UWB applications.

Computational analysis of a dual‐port semi‐circular patch antenna combined with Koch curve fractals for ultra‐wideband systems

AbstractThis paper presents a two‐port microstrip‐fed semi‐circular patch antenna integrated with Koch curve fractals and common ground with defected ground structure for the effective implementation in handheld ultra‐wideband (UWB) systems. The proposed array is engraved on a 1.57 mm thick FR‐4 substrate with an overall array size of 30.5 × 47 × 1.64 mm3. The parametric analysis of the proposed array indicates that the two optimized Koch curve fractal (second iteration order) radiators (upper substrate layer) provides an optimum matching performance in a wide operational band (4.395–10.184 GHz, 79.4%) and minimizes the patch area by 41.2% as compared to the conventional circular patch. To realize good port‐to‐port isolation (S21/S12 ≤ −16.8 dB), the reduced ground is slotted and incorporated with a funnel‐shaped decoupling structure at the center. The prototype of the proposed array is fabricated and experimentally tested to justify the simulated S‐parameter results. All diversity metrics like envelope correlation coefficient, diversity gain (DG), mean effective gain, channel capacity loss, and total active reflection coefficient lie within their acceptable limits which affirm a high signal‐to‐noise ratio and the proficiency of the proposed array in the development of high data‐rate UWB communication devices.

Differential Permutation Index DCSK Modulation for Chaotic Communication System

This letter proposes a differential permutation index differential chaos shift keying (DPI-DCSK) modulation for wireless communications. The conventional PI-DCSK has the disadvantage of wasting transmission energy and the loss of system performance. In $M$ -ary DPI-DCSK, one chaotic sequence to be sent represents current modulated ${M}$ -ary symbol as well as the reference of next modulation symbol in a data frame, which can fully utilize the transmission energy with the same hardware implementation as PI-DCSK. The bit error performance of the proposed DPI-DCSK over the multipath Rayleigh fading channel is theoretically analyzed. The simulation results show that the proposed DPI-DCSK achieves a performance gain of more than 3 dB over PI-DCSK, especially in high-delay multipath fading channels. The performance advantage of the proposed scheme is also illustrated in practical ultra-wideband (UWB) channels. Thus, DPI-DCSK is an efficient alternative transmission scheme for chaos-based wireless communication, such as indoor applications of transmitted-reference UWB communications.

High isolation 4-element ACS-fed MIMO antenna with band notched feature for UWB communications

AbstractIn this paper, a compact 4-port band-notched multi-input-multi-output (MIMO) antenna with asymmetric coplanar strip (ACS) feed is presented for ultra-wide band (UWB) applications. The MIMO antenna is comprised of four semi-elliptical radiators with ACS feed for UWB applications and it is printed on inexpensive FR4 substrate of size 48 × 52 mm2 with ɛr = 4.4 and 1.6 mm height. The impedance characteristics of the suggested MIMO antenna ranges from 2.7 to 11 GHz with a band-notched behavior from 3 to 4 GHz to reduce the interception with WiMAX applications, and the isolation level over the achieved band is more than 20 dB between any two adjacent elements. Moreover, the radiation pattern of the proposed UWB antenna is almost omnidirectional with an average realized gain of 3.5 dBi over the entire achieved frequency band. The proposed ACS-fed antenna is confirmed by fabricating and measuring it's impedance and radiation characteristics. Finally, good consistency between simulation and measured outcomes is obtained confirming the validity of the MIMO antenna for real-life UWB wireless systems.

Spoof Surface Plasmon Polariton Delay Lines for Terahertz Phase Shifters

The terahertz gap attracted interest of researchers with its captivating properties such as its potential for ultrawideband communication and high-resolution imaging applications, which require robust and efficient terahertz components and circuits. Terahertz spoof surface plasmon polaritons are perfect alternatives to implement terahertz integrated circuits. We present the first-time demonstration of the terahertz spoof surface plasmon polariton delay lines for terahertz phase shifters, which present an unprecedented insertion phase versus loss performance. The electrical lengths of the proposed delay lines are tuned just by changing the corrugation depths, which allows the designer to keep the physical length of the delay lines constant. In order to verify the proposed idea, four different delay lines having the same length of 1052.5 μm are designed, where the electrical lengths of the delay lines are selected to represent the four different phase states of a 2-bit phase shifter. The measurement results of the fabricated terahertz delay lines show almost perfect phase accuracy and very good agreement with the simulations, having an ultra-low average phase error of 0.6%, and average insertion and return losses of −2.3 and −18 dB, respectively. These measurements result in, to the best of our knowledge, a record-high figure-of-merit of 90°/dB compared to all other kinds of planar waveguides at 0.3 THz. The proposed delay lines emerge as a very high-performance and promising candidate for all the waveguide-based components that are crucial for the terahertz integrated circuits.

A Survey of Autonomous Vehicles: Enabling Communication Technologies and Challenges

The Department of Transport in the United Kingdom recorded 25,080 motor vehicle fatalities in 2019. This situation stresses the need for an intelligent transport system (ITS) that improves road safety and security by avoiding human errors with the use of autonomous vehicles (AVs). Therefore, this survey discusses the current development of two main components of an ITS: (1) gathering of AVs surrounding data using sensors; and (2) enabling vehicular communication technologies. First, the paper discusses various sensors and their role in AVs. Then, various communication technologies for AVs to facilitate vehicle to everything (V2X) communication are discussed. Based on the transmission range, these technologies are grouped into three main categories: long-range, medium-range and short-range. The short-range group presents the development of Bluetooth, ZigBee and ultra-wide band communication for AVs. The medium-range examines the properties of dedicated short-range communications (DSRC). Finally, the long-range group presents the cellular-vehicle to everything (C-V2X) and 5G-new radio (5G-NR). An important characteristic which differentiates each category and its suitable application is latency. This research presents a comprehensive study of AV technologies and identifies the main advantages, disadvantages, and challenges.

Negative Group Delay Circuits and Applications: Feedforward Amplifiers, Phased-Array Antennas, Constant Phase Shifters, Non-Foster Elements, Interconnection Equalization, and Power Dividers

With the rapid development of newgeneration communication technology such as multiple-input/multiple-output technology, ultrawideband communication, and 5G technology, communication systems have higher requirements for the quality of signal transmissions. Achieving this quality requires attention not only to signal amplitude characteristics but also to phase characteristics because of the long delays and signal distortion that come with positive group delay (PGD). However, negative group delay (NGD) circuits are an effective way to compensate for PGD and decrease the variability of passband group delay.

An experimental analysis of image extract algorithm in UWB communication medium to make a smart pesticide sprayer for cassava agriculture crops

This paper presents an ultra-wide band (UWB) based hardware prototype model to study a novel image extract algorithm (IEa). The IEa is a less complex algorithm proposed to solve the issue which arises due to the attack of pests in cassava agriculture land in eastern part of India, Nagaland. The hardware prototype model is made around Raspberry Pi 3 B+ board that supports 2.4 GHz and 5 GHz IEEE 802.11.b/g/n/ac wireless local area network (WLAN). The hardware system is able to spray pesticides automatically and uniformly (using nozzle system) once the pest is detected. During implementation of this device using IEa algorithm in agriculture field, it is found that time consumption is less as compared to other similar existing algorithms to protect agriculture crops from pest. The total processing time of the algorithm consumed by the device for detecting pests in an agriculture field was found to be 17.10 seconds.

High-Precision Multipath-Based Indoor Localization Scheme With User Privacy Protection for Dynamic NLoS Environments

High-precision indoor localization systems (ILSs) are critical for applications such as human smartphone navigation, autonomous robotics and automated warehouse and factory design. This paper presents a novel fingerprinting-based ILS, which features a decimeter-level localization accuracy, the ability to function in a constantly changing non line-of-sight (NLoS) environment, and user privacy protection without the need for heavy computations. The proposed ILS is able to maintain its localization accuracy in a constantly changing environment and to camouflage the user’s location by leveraging multipath propagation. The method was successfully tested both by experimental verification using the ultra-wideband communication standard and a ray-tracing simulation. An average localization error of 6 cm is demonstrated for a stationary or slow-moving receiver. An average error of 30 cm is demonstrated for a receiver that is moving at a fast walking pace. The obtained localization accuracy is comparable to the accuracy of the state-of-the-art localization algorithms. At the same time, the proposed approach solves two practical challenges faced by ILSs: robustness to changing environments with moving objects and the high computation requirements of user privacy protection. The high degree of user privacy was evaluated using a set of corresponding metrics.

Chaos-control and parallel queue synchronization of laser local area network

In this work, we study the chaos-control and parallel queue synchronization of a laser local area network (LAN). We present and study specifically a “single-queue-double-parameter” method of the parallel series queue dynamic behavior synchronization of the controlled laser LAN under two optoelectronic delay feedback controllers, and establish the mathematical and physical model of the controlled laser LAN. The LAN node is composed of two space coupled lasers with different parameters and other two single lasers, where two lasers series produce two different parallel queues, which results in two different chains of LAN nodes. Optical LAN links are composed of two optical parallel-crossing paths and two photoelectric delay feedback controllers setting in two lasers of LAN, which creates a method of double-parameter control of LAN. Through the analysis of the stability theory of differential equation and the dynamic characteristic equation of coupled lasers of LAN, our mathematical theory demonstrates that the chaos-control of laser LAN can be achieved by two photoelectric delay feedback controllers adjusting photoelectric feedback levels and feedback delay time of one of the two coupled laser and another single laser, respectively. Making analysis of the stability theory of differential equation and the dynamic characteristic equation of LAN nodes in two queue chains, we demonstrate theoretically how to obtain synchronization in network nodes of the controlled LAN on two queue chains by controlling optical feedback levels, and by the photoelectric delay feedback controllers adjusting photoelectric feedback levels and feedback delay time, respectively. Using our numerical calculation of parallel queue synchronization, the node laser’s waveform and its phase space trajectory, we find that very lasers of network nodes of the controlled LAN can lead to the parallel queue synchronization of a double-period, a three-period, a four-period and other quasi-periods while these quasi-periodic synchronizations and dynamic synchronizations are controlled in two queue chains of LAN nodes when we let the photoelectric feedback level and the delay time shift on some parameters. We find also two controlled quasi-periodic parallel queue synchronization regions. This paper also presents an application case of laser LAN multi-point chaotic carrier synchronous emission and ultra-wideband communication. This is a new type of controlled laser LAN system, which has the core elements of optical LAN and the characteristics of multi-variable, multi-dimension and parallel queue chaos-control techniques of complex dynamic networks. It also has the function of optical network ultra-wideband communication. The results have important reference value for studying the LAN, optical network and its synchronization and control, laser technology and chaos.

High gain 0.18 μm-GaAs MMIC cascode-distributed low-noise amplifier for UWB application

This paper describes a design of 3 GHz–12 GHz MMIC distributed Low Noise Amplifiers (LNAs) for Ultra Wideband communications systems. The proposed circuit is a common source and cascode topology using a standard 0.18 μm ED02AH process from OMMIC foundry. The ultra-wideband LNA achieves a power gain of 16.9 ± 1.7 dB and an average noise figure of 2.9 ± 0.58 dB. The input and output reflection coefficients are less than −10 dB, the reverse gain S12 is less than −37dB and a high linearity IIP3 of [4–6.2] dBm. The chip area including testing pads is only about 1.3 × 1.3 mm2.

Designing Complementary Sequence Sets With Impulse Like Complementary Auto-Correlation Function

In this letter, we address the problem of designing unit modulus complementary sequence set with impulse-like complementary auto-correlation function which has immense potential with applications in ultra wide-band (UWB) communication system, code-division multiple-access (CDMA) system and active sensing systems like MIMO RADAR and SONAR. We have formulated the design problem as the minimization of complementary peak side-lobe level and proposed a monotonic algorithm based on the majorization-minimization technique. Through numerical simulations, we show the construction of sequence sets (of different lengths) with impulse like complementary auto-correlation - which is first of its kind in the sequence design literature. We also discuss the computationally efficient implementation of the proposed algorithm via FFT, IFFT operations.

Stable Phaseless Sampling and Reconstruction of Real-Valued Signals with Finite Rate of Innovation

A spatial signal is defined by its evaluations on the whole domain. In this paper, we consider stable reconstruction of real-valued signals with finite rate of innovation (FRI), up to a sign, from their magnitude measurements on the whole domain or their phaseless samples on a discrete subset. FRI signals appear in many engineering applications such as magnetic resonance spectrum, ultra wide-band communication and electrocardiogram. For an FRI signal, we introduce an undirected graph to describe its topological structure, establish the equivalence between its graph connectivity and its phase retrievability by point evaluation measurements on the whole domain, apply the graph connected component decomposition to find its unique landscape decomposition and the set of FRI signals that have the same magnitude measurements. We construct discrete sets with finite density so that magnitude measurements of an FRI signal on the whole domain are determined by its phaseless samples taken on those discrete subsets, and we show that the corresponding phaseless sampling procedure has bi-Lipschitz property with respect to a new induced metric on the signal space and the standard $\ell ^{p}$ -metric on the sampling data set. In this paper, we also propose an algorithm with linear complexity to reconstruct an FRI signal from its (un)corrupted phaseless samples on the above sampling set without restriction on the noise level and apriori information whether the original FRI signal is phase retrievable. The algorithm is theoretically guaranteed to be stable, and numerically demonstrated to approximate the original FRI signal in magnitude measurements.

Area- and Energy-Efficient Sub-GHz Impulse Radio UWB Transmitter With Output Amplitude Enhancement for Biomedical Implants

This brief presents an almost fully digital edge-combining impulse radio ultra-wideband (UWB) transmitter. The proposed output amplitude enhancement technique increases the peak-to-peak amplitude of the UWB output pulse to more than two times that of the traditional UWB transmitter. The pulse width adjustment circuit is designed to ensure the robustness of the UWB circuit against process, supply voltage, and temperature variations. The output power spectrum density of this transmitter is primarily concentrated in the range of 0-960 MHz and can satisfy the mask requirement of the Federal Communication Commission for UWB communication. The proposed UWB transmitter is implemented in a 0.18- μm CMOS process and occupies an area of 97.41 × 68.6 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The measurement results of 20 samples indicate that the average output amplitude is 106.02 mV at a supply voltage of 1 V. At the data transmission rate of 50 Mbps, the measured energy consumptions are 11.18 and 3.97 pJ/bit, respectively, at the supply voltages of 1 and 0.8 V.

Time-shift immunity for wireless sensor network based on discrete wavelet packets

Wavelet-based Ultra Wide Band communications rely on receiver collecting data simultaneously from many transmitters and without interference thanks to the orthogonality between primitive wavelet packets. Nevertheless, there is a particular case for which the communication fails. Indeed, the time-shift between primitive wavelet packets results in a loss of the orthogonality of these wavelet packets. This paper proposes an asynchronous Impulse Radio-Ultra Wide Band (IR-UWB) transmission suitable in Wireless Sensor networks without any distinction between the transmitters. The originality of the proposed solution is to ensure a time-shift immunity of IR-UWB receivers by finding the unique combination of shifted primitive packets. For this purpose, finding the one zero result of successive subtractions between received and primitive packets is performed. Considering a given wavelet, the proposed solution is able to decode the shifted-mixed primitive packets from multiple transmitters whatever the time-shift between each packets.