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Electronic prostheses require a communication link to other on-body nodes, for example, for control signal extraction. This link can be made wireless to improve user experience compared to wired solutions. Even though ample on-body communication techniques have been described for wireless body area networks, in prosthetics, the efficiency of wireless links is often neglected, in particular when radio frequency (RF) antennas are used. This work aims to show the benefit of on-body RF antenna design for prosthetics, by developing a dedicated antenna for use in a lower arm prosthesis. Additionally, this work tries to fill a gap in literature, where some antennas for dedicated on-body RF communication are presented, but no antennas specific for communication along the arm exist. To this aim, numerical simulations are performed using a cylindrically layered arm model to design a novel, electrically small, capacitively loaded, meandered, 2.45 GHz monopole antenna. The antenna is fabricated using 3D printed polylactic acid and validated both in a static human arm channel and in a dynamic setting, where the human subject performs various tasks. This antenna outperforms an off-the-shelf printed circuit board (PCB) antenna by 18 dB and a rectangular patch antenna by 4 dB in terms of link budget at a separation distance of 20 cm, both in line of sight and non-LOS path loss experiments. Additionally, while performing four commonplace activities, the average power received increased by 20 dB in an on-body link established between two of our novel antennas rather than two of the PCB antennas. These results will aid in the development of wireless prostheses used by a growing number of amputees.

The objective of this paper is to develop a wearable circular UWB MIMO antenna array, consisting of four elements, that is capable of detecting and locating tumor cells within a heterogeneous breast phantom. The antenna element operates within a bandwidth from 2.4 GHz to 10.6 GHz when FR4 is used as the substrate, and extends from 2.57 GHz to 12.6 GHz when a Dacron fabric is used instead. The antenna is fabricated and measured, yielding highly similar results to the simulated outcomes. In the suggested detection system, one antenna is used for transmission, while the other antennas receive the transmitted signal. The employed antenna demonstrates gains of 5.49 dBi, 9.87 dBi, 11.9 dBi, and 14.7 dBi at resonant frequencies of 2.84 GHz, 3.87 GHz, 5.83 GHz, and 8.24 GHz, respectively, when a Dacron fabric is used as the substrate. Moreover, the proposed antenna exhibits a flexible shape with minimal vertical and horizontal bending effects across the entire operating frequency band. The antenna has a compact size of 42.85 × 42.85 mm2 and is printed on an FR4 substrate with a dielectric constant of 4.5 and a thickness of 1.6 mm for testing purposes. The S-parameters of the suggested system can effectively identify and precisely locate small tumors. Furthermore, the SAR findings indicate that the amount of power absorbed by the breast phantom tissues complies with the IEEE standards, thus confirming the suitability of the recommended antenna for the early detection and localization of breast cancer.

In this work, two elements (with two versions) compat UWB MIMO antennas are designed and fabaricted. CST software is used in the simulation process. The two elements MIMO antenna have a size of 29.5 × 60 mm2. Measured S parameters show that the MIMO antennas work well from 3 GHz up to 20 GHz (representing the maximum working frequency of the measurent instrumnts). Mesurement results show that the isolation between the antenna elemnts is higher than 23 dB for the first version of the two elements UWB MIMO antenna. In addition, mesurement results show that the isolation between the antenna elemnts is higher than 30 dB for the second version of the two elements UWB MIMO antenna. Measurements show a channel capacity loss lower than 0.4 bps/Hz and a low group delay variation.

In this paper, a miniaturized textile microstrip antenna is proposed for wireless body area networks (WBAN). The ultra-wideband (UWB) antenna used a denim substrate to reduce the surface wave losses. The monopole antenna consists of a modified circular radiation patch and an asymmetric defected ground structure, which expands impedance bandwidth (BW) and improves the radiation patterns of the antenna with a small size of 20 × 30 × 1.4 mm3. An impedance BW of 110% (2.85–9.81 GHz) frequency boundaries was observed. Based on the measured results, a peak gain of 3.28 dBi was analyzed at 6 GHz. The SAR values were calculated to observe the radiation effects, and the SAR values obtained from the simulation at 4/6/8 GHz frequencies followed the FCC guideline. Compared to typical wearable miniaturized antennas, the antenna size is reduced by 62.5%. The proposed antenna has good performance and can be integrated on a peaked cap as a wearable antenna for indoor positioning systems.

Partial discharges (PD) are the most common and harmful threat to the health of electrical insulation of high voltage (HV) and high field (HF) equipment. The occurrence of PD activity in HV and MV equipment is at the same time a cause and a sign of insulation degradation that may eventually result in the breakdown of the HV power equipment. For the safe and reliable operation of HV power equipment, continuous PD monitoring needs to be conducted conveniently to prevent any unplanned power outages and damage to electrical power equipment. The ultra-high frequency (UHF) PD measurement method has been widely used as an effective technique to detect PD activity on HV power equipment due to its non-invasive principle. To enable PD detection accuracy, there is still a need for more sensitive PD sensors that can assist the UHF PD monitoring system by suppressing ambient background noise and low-frequency electromagnetic interferences from telecommunication such as GSM signals. To tackle the sensitivity issues, this article presents a new design of ultra-wideband (UWB) microstrip patch antenna that is capable of effective suppression of low-frequency interference signals. The proposed antenna, designed, simulated, and optimized using the CST Microwave Studio software, has a bandwidth of 3.3GHz, below -10dB, in the operating frequency range of 1.2GHz-4.5GHz. The prototype of this antenna, printed on an FR4 substrate of a thickness of 1.6mm and a dielectric constant of 4.4, featuring a compact size of 100mm $\times100$ mm $\times1.6$ mm, was implemented to detect PD through laboratory experiments. This paper shows that the designed UWB antenna has high sensitivity, good noise rejection and it is, therefore, a promising candidate sensor for PD detection on HV equipment.

The research presents mutual coupling reduction between UWB-MIMO antenna elements using stub loading technique. The proposed 2 × 2 UWB antenna geometry consists of two circular-shaped monopole radiators with a partial ground for perfect impedance matching. Stubs of 20 mm × 0.2 mm are inserted between the two antenna elements in the ground plane to improve the isolation. The decoupling stub leads to a mutual coupling reduction of less than 20 dB. The farfield measurement at a selected frequency of 10 GHz confirms an omnidirectional radiation pattern. Different MIMO antenna metric such as channel capacity loss (CCL), mean effective gain (MEG), total active reflection coefficient (TARC), envelope correlation coefficient (ECC), and surface current are presented. Details of the design considerations and the simulation and measurement results are presented and discussed. The proposed MIMO antenna array can be well suited for UWB applications.

This paper presents a compact CPW-fed MIMO antenna for UWB applications. The four-element CPW-fed antenna is designed as a radiator. The isolations between the same polarized elements and the orthogonally polarized elements are more than 20 and 25 dB, respectively. The floating parasitic element is used to improve isolation at a higher frequency. The simulated and measured 10 dB impedance bandwidth of the proposed MIMO UWB antenna is from 3.6 to 10.3 GHz. The return loss, isolation, radiation patterns, envelope correlation coefficient (ECC), total active reflection coefficient (TARC), diversity gain (DG), and channel capacity loss (CCL) are simulated and/or measured for the proposed antenna. ECCs are less than 0.0022, DGs are above 9.9 dB, TARC has minimum variations in different angles and CCLs are less than 0.4 bits/s/Hz at 10 dB impedance bandwidth. Due to which the proposed antenna can be used in portable UWB applications.

In the design of conventional microwave devices, the parameters need to be continuously optimized to meet the desired targets, and the whole process is time-consuming and laborious. As a surrogate model, machine learning is an effective optimization method. However, in the modeling process, the high-dimensional data processing and the complex nonlinear relationship between parameters is a problem to be solved. This paper proposes a deep learning model for designing UWB antennas, which determines the model structure of deep belief network (DBN) by particle swarm algorithm (PSO), and then combines DBN and extreme learning machine (ELM). The proposed model can obtain higher feature learning capability and nonlinear function approximation capability, and has been applied to the optimal design of the whole structure of the fractal antenna and the notch structure of the MIMO antenna, and its S-parameters are well fitted while meeting the requirements of the design targets. The DBN-ELM method obtains the good results when compared with common modeling methods using the same training samples (the root mean square error tested is 11.87% in the fractal antenna and 3.56% in the MIMO antenna). Overall, the proposed DBN-ELM model has higher predictive and generalization capabilities, which can also be used to model more complex antenna structures.

This paper investigates an ultra-wideband (UWB) antenna with a triple-rectangular notch band at 5G, WLAN, and Satellite downlink bands. The 5G and WLAN bands are notched by using a pair of electromagnetic bandgap (EBG) structures while the satellite downlink band is notched by using two split-ring resonators (SRRs). The EBG structure is a metallic conductor loaded on the backside of the radiator which is connected to the patch via a shorting pin. The SRRs consist of a pair of metallic rings etched on the backside of the feedline. The simulated and measured results show that the proposed antenna has an operational bandwidth from 3.1 – 11.8 GHz for $\vert \text{S}11\vert rejecting 5G sub-6 GHz (3.4 – 3.9 GHz), WLAN (5.15 – 5.825 GHz), and satellite downlink band (7.25 – 7.75 GHz) signals with high selectivity. The peak gain of the UWB antenna is 3.86 dBi but it sharply decreases up to -13 dBi at stop-bands. The antenna also has additional advantages of the overall compact size ( $20\times 26\times1.52$ mm3) with stable gain and radiation patterns at the pass-bands.

To meet the anti-interference and multi-function requirements of the antenna, a compact 8-states frequency reconfigurable ultra-wideband (UWB) monopole antenna is proposed. The antenna consists of a coplanar waveguide structure (CPW), defected ground structure (DGS), rectangular radiation patch, and stepped feed line. Band rejections at the C band, WLAN, and X band are generated by two C-slots and inverted U-slot, respectively. Three PIN diodes are connected across the C-slots and inverted U-slot. By controlling the on/off state of PIN diodes to realize notch reconfiguration. The antenna size is only 22 mm $\times 13$ mm $\times0.8$ mm. The measured results show that the antenna can work in 8 states. The impedance bandwidth of UWB mode is 2.82-13.25 GHz, the relative bandwidth is 129.8%. The notch band is 3.19-4.58 GHz, 5.26-6.21 GHz, and 7.87-8.73 GHz, respectively. The antenna has stable gain, good omnidirectional radiation performance, and can switch freely between UWB mode and each notch band mode.

In this paper, we present a modified UWB antenna with hexagonal slotted ground plane inspired with a double combined symmetric T-shaped slots and dual rotated L-shaped strip for dual band notched characteristics. Initially, the operating frequency range is from 3GHz to 12 GHz. To eliminate the unwanted C-band (3.625-4.2GHz) and the entire uplink and downlink of X-band satellite communication systems (7.25 -8.39 GHz) frequency bands, we are investigating the conventional UWB patch antenna and loaded it with a mentioned strips and slots respectively. The performances of the antenna are optimized both by CST Microwave Studio and Ansoft HFSS. To further analyze the parametric effects of the slots and strips, the surface current distribution is presented and discussed. The antenna gain versus frequency gives an acceptable value except the notched band regions, these values are reduced from its normal to be a negative in the notched bands (3.625-4.2GHz) and (7.25 to 8.39 GHz).

In this paper, design and analysis of a polygonal shaped patch antenna for on-body applications is presented. The patch antenna simulated to operate on ultra-wide band (UWB) frequency range with the dimensions of the 22.5 mm x 38 mm x 0.5 mm. The substrate material of antenna is Roger-RO4003, which has a relative permittivity of 3.55 and loss tangent of 0.0027. The antenna resonates from the 1.26 GHz to 11.1 GHz efficiently. In the paper, characteristic specifications of antenna such as return loss, gain and radiation patterns are given and interpreted successively. In the simulation, 3 biological layers consisting of skin, fat and muscle defined to represent the human body and the simulation has been done using these layers. Proposed antenna can be used in the applications such as medical, industrial, information systems, positioning systems etc. In addition to this, the small profile of the antenna makes it portable and suitable for ultra-wide band on-body applications., {"references":["Hashemi, A., Nourbakhsh, S., Tehrani, P., & Karimi, A. Remote telemonitoring of cardiovascular patients: Benefits, barriers, new suggestions. Artery Research, 2018; 22, 57-63.","Mohammadzadeh, N., & Safdari, R. Patient monitoring in mobile health: opportunities and challenges. Medical Archives, 2014; 68(1), 57","Paolini, G., Masotti, D., Antoniazzi, F., Cinotti, T. S., & Costanzo, A. Fall detection and 3-D indoor localization by a custom RFID reader embedded in a smart e-health platform. IEEE Transactions on Microwave Theory and Techniques, 2019; 67(12), 5329-5339.","Hall, P. S., & Hao, Y. Antennas and propagation for body-centric wireless communications. 2012. Artech house.","Yan, S., Soh, P. J., & Vandenbosch, G. A. Wearable ultrawideband technology—A review of ultrawideband antennas, propagation channels, and applications in wireless body area networks. IEEE Access, 2018; 6, 42177-42185.","Kiani, S., Rezaei, P., & Fakhr, M. A CPW-fed wearable antenna at ISM band for biomedical and WBAN applications. Wireless Networks, 2021; 27(1), 735-745.","Abohmra, Abdoalbaset, et al. Novel flexible and wearable 2.4 GHz antenna for body-centric applications. 2019 IEEE Intl Conf on Dependable, Autonomic and Secure Computing, Intl Conf on Pervasive Intelligence and Computing, Intl Conf on Cloud and Big Data Computing, Intl Conf on Cyber Science and Technology Congress (DASC/PiCom/CBDCom/CyberSciTech). IEEE, 2019.","Garg, R., Bhartia, P., Bahl, I. J., & Ittipiboon, A. Microstrip antenna design handbook. 2021. Artech house.","Balanis, Constantine A. Antenna theory: analysis and design. 2016. John Wiley sons.","https://www.fcc.gov/general/body-tissue-dielectric-parameters."]}

In this paper, a comparison of two ground penetrating radar (GPR) systems is presented, the classical bi-static one and the Multiple Input Multiple Output (MIMO) system both using N Vivaldi antennas. For both configurations a Linear Sampling Method (LSM) imaging algorithm and Kirchhoff migration technique are used for target detection and localization. Their performance are compared through a parametric study based on synthetic data modeling a GPR scene.

A low-profile Multiple Input Multiple Output (MIMO) antenna showing dual polarization, low mutual coupling, and acceptable diversity gain is presented by this paper. The antenna introduces the requirements of fifth generation (5G) and the satellite communications. A horizontally (4.8–31 GHz) and vertically polarized (7.6–37 GHz) modified antipodal Vivaldi antennas are simulated, fabricated, and integrated, and then their characteristics are examined. An ultra-wideband (UWB) at working bandwidths of 3.7–3.85 GHz and 5–40 GHz are achieved. Low mutual coupling of less than −22 dB is achieved after loading the antenna with cross-curves, staircase meander line, and integration of the metamaterial elements. The antennas are designed on a denim textile substrate with εr = 1.4 and h = 0.5 mm. A conductive textile called ShieldIt is utilized as conductor with conductivity of 1.8 × 104. After optimizing the proposed UWB-MIMO antenna’s characteristics, it is increased to four elements positioned at the four corners of a denim textile substrate to be employed as a UWB-MIMO antenna for handset communications, 5G, Ka and Ku band, and satellite communications (X-band). The proposed eight port UWB-MIMO antenna has a maximum gain of 10.7 dBi, 98% radiation efficiency, less than 0.01 ECC, and acceptable diversity gain. Afterwards, the eight-ports antenna performance is examined on a simulated real voxel hand and chest. Then, it is evaluated and compared on physical hand and chest of body. Evidently, the simulated and measured results show good agreement between them. The proposed UWB-MIMO antenna offers a compact and flexible design, which is suitably wearable for 5G and satellite communications applications.

The design, simulation, realization, and measurement of an ultra-wideband (UWB) antenna on a polymeric substrate have been realized. The UWB antenna was prepared using conventional technology, such as copper etching; inkjet printing, which is regarded as a modern and progressive nano-technology; and polymer thick-film technology in the context of screen-printing technology. The thick-film technology-based UWB antenna has a bandwidth of 3.8 GHz, with a central frequency of 9 GHz, and a frequency range of 6.6 to 10.4 GHz. In addition to a comparison of the technologies described, the results show that the mesh of the screens has a significant impact on the quality of the UWB antenna when utilizing polymeric screen-printing pastes. Last but not least, the eco-friendly combination of polyimide substrate and graphene-based screen-printing paste is thoroughly detailed. From 5 to 9.42 GHz, the graphene-based UWB antenna achieved a bandwidth of 4.42 GHz. The designed and realized UWB antenna well exceeds the Federal Communications Commission’s (FCC) standards for UWB antenna definition. The modification of the energy surface of the polyimide substrate by plasma treatment is also explained in this paper, in addition to the many types of screen-printing pastes and technologies. According to the findings, plasma treatment improved the bandwidth of UWB antennas to 5.45 GHz, and the combination of plasma treatment with graphene provides a suitable replacement for traditional etching technologies. The characteristics of graphene-based pastes can also be altered by plasma treatment in terms of their usability on flexible substrates.

This paper presents an Antipodal Vivaldi Antenna (AVA) design, focusing on its constructional aspects. The main features analysed are the connector attachment structure and the introduction of a polytetrafluoroethylene (PTFE) part that supports the antenna laminate. Issues related to dielectric penetration by milling tools are also addressed. The proposed AVA was manufactured through a low-cost prototyping process and tested, achieving an operational bandwidth from 5 to 18 GHz for a reflection coefficient less than −10 dB and an average gain of 6.23 dBi. The prototype meets all design requirements, which shows the viability of the developed radiator.

A multiple-input-multiple-output (MIMO) ultra-wideband (UWB ) printed bent antenna, suitable for MB-OFDM ECMA-368 system integration with the wireless universal serial-bus (WUSB) dongle is proposed. The antenna consists of two antenna elements with an overall area of 18 X 53 mm2. Each antenna element is a simple modified folded-monopole fed by a coplanar waveguide (CPW). The design process of proposed MIMO UWB CPW-fed bent antenna configuration is presented in four simple steps. Experimental results show that the proposed design has a good impedance bandwidth in the range of 2.95–18.55 GHz with 147.2% fractional bandwidth (FBW). Moreover, the proposed antenna enjoys, low envelope correlation coefficient (ECC), good diversity gain (DG), low total active reflection coefficient (TARC) and omnidirectional radiation patterns. The bit error rate (BER) of the overall MB-OFDM ECMA-368 system with the existence of the proposed MIMO UWB CPW-fed bent antenna is evaluated in more realistic transmission channel scenario by using the extracted transmitting and receiving UWB antennas transfer functions.

In this article, a single-layer frequency selective surface (FSS)-loaded compact coplanar waveguide (CPW)-fed antenna is proposed for very high-gain and ultra-wideband applications. At the initial stage, a geometrically simple ultra-wideband (UWB) antenna is designed which contains CPW feed lines and a multi-stub-loaded hexagonal patch. The various stubs are inserted to improve the bandwidth of the radiator. The antenna operates at 5–17 GHz and offers 6.5 dBi peak gain. Subsequently, the proposed FSS structure is designed and loaded beneath the proposed UWB antenna to improve bandwidth and enhance gain. The antenna loaded with FSS operates at an ultra-wideband of 3–18 GHz and offers a peak gain of 10.5 dBi. The FSS layer contains 5 × 5 unit cells with a total dimension of 50 mm × 50 mm. The gap between the FSS layer and UWB antenna is 9 mm, which is fixed to obtain maximum gain. The proposed UWB antenna and its results are compared with the fabricated prototype to verify the results. Moreover, the performance parameters such as bandwidth, gain, operational frequency, and the number of FSS layers used in the proposed antenna are compared with existing literature to show the significance of the proposed work. Overall, the proposed antenna is easy to fabricate and has a low profile and simple geometry with a compact size while offering a very wide bandwidth and high gain. Due to all of its performance properties, the proposed antenna system is a strong candidate for upcoming wideband and high-gain applications.

This article presents an ultra-wideband (UWB) monopole antenna with triple band notch characteristics. The proposed antenna consists of an octagonal patch, fed with a 50 Ω line, which occupies a compact size of 40 mm × 29 mm (0.36λ × 0.26λ, λ is computed using 2.7 GHz frequency) and resonances at a relatively low frequency (2.94 GHz). Specifically, an L-shaped stub, an inverted C-shaped slot, and a pair of U-shaped resonating structures are introduced into the design, which allow antenna to generate three band notches at 3.22–3.83 GHz, 4.49–5.05 GHz and 7.49–8.02 GHz, corresponding to WiMAX band, Indian national satellite (INSAT) band, and X-band satellite frequencies, respectively. In the center of the notched band, the antenna has lower efficiency and gain, essentially indicating that the antenna has good interference rejection performance. To evaluate its performance, the proposed antenna has been fabricated and measured, and the relevant functional parameters, such as S-parameters, voltage standing wave ratio (VSWR) and radiation property, have been studied.

This paper discusses an elliptical ultrawideband (UWB) antenna and a dual-band UWB notch antenna. To achieve a UWB bandwidth, two corner cuts are etched into the rectangular slot on the partial ground plane. An inverted-U-shaped and conductor-shaped resonator are utilized to achieve dual-band notch characteristics on a partial ground plane. The suggested antenna has an overall dimension of 24×32mm2. The suggested UWB antenna has a gain of 4.9 dB, a bandwidth of 2.5–11 GHz, a linear phase response, a group delay of less than 1 ns, and a steady radiation pattern. The suggested UWB notch rejects WLAN and ITU bands from 5.2–5.7 GHz and 7.2–8.5 GHz, respectively, with an impedance bandwidth of 2.5–11 GHz. The UWB notch antenna features a linear phase, a group delay of less than 1 ns, and a stable radiation pattern.

In this manuscript, a compact in size yet geometrically simple Ultra-Wideband (UWB) antenna is demonstrated. The flexible-by-nature substrate ROGERS 5880, having a thickness of 0.254 mm, is utilized to design the proposed work. The antenna configuration is an excerpt of a traditional rectangular monopole antenna resonating at 5 GHz. Initially, a pair of triangular slots are employed to extend the impedance bandwidth of the antenna. In addition, a semi-circular-shaped, short-ended stub is connected at the upper edges of the patch to further increase the operational bandwidth. After optimization, the proposed antenna offers UWB ranging from 2.73–9.68 GHz, covering almost the entire spectrum allocated globally for UWB applications. Further, the antenna offers a compact size of 15 × 20 mm2 that can easily be integrated into small, flexible electronics. The flexibility analysis is done by bending the antenna on both the x and y axes. The antenna offers performance stability in terms of return loss, radiation pattern, and gain for both conformal and non-conformal conditions. Furthermore, the strong comparison between simulated and measured results for both rigid and bent cases of the antenna, along with the performance comparison with the state-of-the-art, makes it a potential candidate for present and future compact-sized flexible devices.

In this article, we present the design and validation of an efficient chipless RFID system. A multi-resonator chipless tag is designed and tested for high bit coding capacity. A high gain, ultra-wideband step-shape rectangular patch (USRP) antenna is proposed to validate the specificity of the tag in terms of its operation. The devised antenna is evaluated for various performance parameters, which recommend its suitability for testing and validation of high-capacity tags that can be deployed in modern applications, particularly in the Internet of Things (IoT) networks. A measurement setup is established to achieve performance validation of the tag over a significant range of 40 cm. There is close agreement between the measured and simulated results, which suggests that the proposed antenna system can be adopted in a similar measurement setup to test and validate the performance of any chipless RFID tag operating in the same bandwidth meant for IoT networks.

An active reconfigurable ultra-wideband antenna exhibiting complementary frequency notched and narrowband responses is proposed in this paper. The frequency responses are achieved on a CPW fed single element printed monopole antenna loaded with a pair of split ring resonators (SRR) and PIN Diodes. The SRRs and PIN Diodes embedded on the Coplanar Waveguide (CPW) feed works as an inline filter, when activated, exhibits frequency reconfigurability by transforming a frequency notched wideband antenna into a narrowband antenna. Different biasing conditions (reverse and forward) on the loaded PIN diodes toggle between frequency-notched and narrow band response of the antenna. Prototypes are fabricated and the measured impedance and radiation characteristics are presented. This concept offers multi-antenna functionality using a single radiator without any modification or addition to the radiator geometry.

This paper proposes the implementation of and experimentation with GPR for real-time automatic detection of buried IEDs. GPR, consisting of hardware and software, was implemented. A UWB antenna was designed and implemented, particularly for the operation of the GPR. The experiments were conducted in order to demonstrate the real-time automatic detection of buried IEDs using GPR with an R-CNN algorithm. In the experiments, the GPR was mounted on a pickup truck and a maintenance train in order to find the IEDs buried under a road and a railway, respectively. B-scan images were collected using the implemented GPR. R-CNN-based detection for the hyperbolic pattern, which indicates the buried IED, was performed along with pre-processing, for example, using zero offset removal, and background removal and filtering. Experimental results in terms of detecting the hyperbolic pattern in B-scan images were shown and verified that the proposed GPR system is superior to the conventional one using region analysis processing-based detection. Results also showed that pre-processing is required in order to improve and/or clean the hyperbolic pattern before detection. The GPR can automatically detect IEDs buried under roads and railways in real time by detecting the hyperbolic pattern appearing in the collected B-scan image.

In this article, an inkjet-printed circular-shaped monopole ultra-wideband (UWB) antenna with an inside-cut feed structure was implemented on a flexible polyethylene terephthalate (PET) substrate. The coplanar waveguide (CPW)-fed antenna was designed using ANSYS high-frequency structural simulator (HFSS), which operates at 3.04–10.70 GHz and 15.18–18 GHz (upper band) with a return loss &lt, −10dB and a VSWR &lt, 2. The antenna, with the dimensions of 47 mm × 25 mm × 0.135 mm, exhibited omnidirectional radiation characteristics over the entire impedance bandwidth, with an average peak gain of 3.94 dBi. The simulated antenna structure was in good agreement with the experiment’s measured results under flat and bending conditions, making it conducive for flexible and wearable Internet of things (IoT) applications.

Wireless body area network (WBAN) applications have broad utility in monitoring patient health and transmitting the data wirelessly. WBAN can greatly benefit from wearable antennas. Wearable antennas provide comfort and continuity of the monitoring of the patient. Therefore, they must be comfortable, flexible, and operate without excessive degradation near the body. Most wearable antennas use a truncated ground, which increases specific absorption rate (SAR) undesirably. A full ground ultra-wideband (UWB) antenna is proposed and utilized here to attain a broad bandwidth while keeping SAR in the acceptable range based on both 1 g and 10 g standards. It is designed on a denim substrate with a dielectric constant of 1.4 and thickness of 0.7 mm alongside the ShieldIt conductive textile. The antenna is fed using a ground coplanar waveguide (GCPW) through a substrate-integrated waveguide (SIW) transition. This transition creates a perfect match while reducing SAR. In addition, the proposed antenna has a bandwidth (BW) of 7–28 GHz, maximum directive gain of 10.5 dBi and maximum radiation efficiency of 96%, with small dimensions of 60 × 50 × 0.7 mm3. The good antenna’s performance while it is placed on the breast shows that it is a good candidate for both breast cancer imaging and WBAN.

This paper presents the design of a printed step-type monopole antenna for biological tissue analysis and medical imaging applications in the microwave frequency range. The design starts from a very simple and widely known rectangular monopole antenna, and different modifications to the antenna geometry are made in order to increase the bandwidth. The antenna dimensions are optimized by means of a parametric analysis of each dimension using a 3-D electromagnetic simulator based on the finite element method. The optimized antenna, with final dimensions of 40 x 36 mm(2), is manufactured onto a low-cost FR4 (fiber glass epoxy) substrate. The characteristics of the antenna have been measured inside an anechoic chamber, obtaining an omnidirectional radiation pattern and a working frequency range between 2.7 GHz and 11.4 GHz, which covers the UWB frequencies and enables the use of the antenna in medical imaging applications. Finally, the behaviour of four of these antennas located around a realistic breast model, made with biocompatible materials, has been analysed with the electromagnetic simulator, obtaining good results and demonstrating the usefulness of the designed antenna in the proposed application.

У статті представлено проектування та аналіз компактної напівкруглої антени для застосувань UWB діапазону. У статті висвітлено та представлено порівняльне дослідження листоподібної антени з використанням різних матеріалів підкладки. Проведено порівняльний аналіз таких параметрів антени як VSWR, коефіцієнтів підсилення та S11. Компактна листоподібна антена, яка представлена в роботі, розроблена з використанням Rogers RT Duroid 5880 і має розмір 12 х 19 мм2. Розроблена антена забезпечує дуже широку пропускну здатність 4,6-15,01 ГГц (відносна пропускна здатність 106,2 %) і максимальний коефіцієнт підсилення 3,445 дБі при 12,646 ГГц. Ця антена може бути використана для UWB та X-діапазонів. The paper presents the design and analysis of a compact semicircular antenna for UWB applications. The paper highlights and presents the comparative study for a leaf-shaped antenna using various substrate materials. The comparative analysis has been carried out for VSWR, gain, and S11 characteristics of the antenna. The compact leaf-shaped antenna presented in this paper is designed using Rogers RT Duroid 5880 of a size 12 x 19 mm2. The designed antenna achieves a very wide bandwidth of 4.6-15.01 GHz (fractional bandwidth of 106.2 %) and a maximum gain of 3.454 dBi at 12.646 GHz. This antenna can be used for UWB and X-band applications.

This paper presents the design of a printed step-type monopole antenna for biological tissue analysis and medical imaging applications in the microwave frequency range. The design starts from a very simple and widely known rectangular monopole antenna, and different modifications to the antenna geometry are made in order to increase the bandwidth. The antenna dimensions are optimized by means of a parametric analysis of each dimension using a 3-D electromagnetic simulator based on the finite element method. The optimized antenna, with final dimensions of 40 &times, 36 mm2, is manufactured onto a low-cost FR4 (fiber glass epoxy) substrate. The characteristics of the antenna have been measured inside an anechoic chamber, obtaining an omnidirectional radiation pattern and a working frequency range between 2.7 GHz and 11.4 GHz, which covers the UWB frequencies and enables the use of the antenna in medical imaging applications. Finally, the behaviour of four of these antennas located around a realistic breast model, made with biocompatible materials, has been analysed with the electromagnetic simulator, obtaining good results and demonstrating the usefulness of the designed antenna in the proposed application.

In this work, a new ultra-wideband (UWB) antenna design with 2.08GHz to 12GHz impedance bandwidth and triple-band specifications is presented. The proposed antenna is formed by a truncated square patch, a partial ground plane, and a 50Ω microstrip line. Three different types of slots were used in order to induce notched bands. A C-shaped slot is etched on the radiating patch to obtain a notched band in 3.31-4.21GHz for WiMAX. An inverted U-shaped slot in the micro-strip line induces a second notched band in order to reduce the interference with the WLAN [5.04-6.81GHz]. Finally, two inverted L-shaped slots around the micro-ribbon line on the ground plane allow the X-band [9.13 to 10.75GHz]. The antenna has dimensions of 32×28×1.6mm3. The Ansoft software (HFSS) was used to simulate the proposed structure. The simulation results are in good agreement with the measurement results. The antenna shows an omnidirectional radiation pattern.

Reduced lightweight microstrip patch antennas have attracted considerable attention in ultra‐wideband (UWB) applications. In this article, a novel modified circular ultra‐wideband monopole antenna with dual‐band notch characteristics is proposed. A circular split‐ring slot and a mushroom‐electromagnetic bandgap‐type structure are employed to realize the dual‐band notch characteristics. The proposed antenna exhibits the bandwidth of 2.0‐12 GHz with a Voltage Standing Wave Ratio

This paper illustrates the design of a ultra-wideband (UWB) four arms non-conventional sinuous antenna for radar electronic support measures (RESM) systems. The antenna works from 1.5 GHz to 18 GHz with a slant 45 polarization ensuring good matching impedance and stable radiative performances. The installation on platform is simplified by exploiting several miniaturization techniques that allows to obtain a definitive diameter of 6 cm. The radiating element exhibits directive stable patterns, good polarization purity and high realized gain in the whole frequency band. Finally the design provides an effective miniaturization of the sinuous antenna with encouraging simulation results.

A printed monopole patch Ultra Wide Band (UWB) antenna for use in UWB application is proposed in this paper. The proposed antenna consists of a patch with appropriate dimensions on one side of a dielectric substrate, and a partial ground plane on the other side of the substrate. The techniques that used to enhance the bandwidth are the partial ground plane, feed point position and adjusted feed gap. The substrate that is used in the proposed antenna is Fr4 epoxy, the optimum dimensions of the antenna are 40mm×28mm×1.5mm this antenna designed by HFSS program. The band achieved by the proposed antenna is from 3.6GHz to 15GHz. This antenna is fabricated in the ministry of science and technology Baghdad-Iraq and a good agreement between simulation and measured S11 is achieved.

A triple-notch band planar ultra-wideband (UWB) antenna is proposed for wireless body area networks (WBANs) to suppress unwanted signals of conventional narrow band communication technologies. These notch bands are WiMAX (3.3–3.8 GHz), WLAN (5.1–5.825 GHz), and ${X}$ -band downlink satellite communication systems (7.25–7.75 GHz). A complementary split ring resonator slot and two L-shaped stubs are introduced on an elliptical-shaped radiating patch to obtain UWB coverage from 2.9 to 12 GHz with three notch bands. The overall antenna structure is fabricated on FR4 substrate with a size of $12\,\,\text {mm} \times 19\,\,\text {mm}$ which provides a size reduction of more than 42% with respect to recent literature. The simulated and measured results indicate that the proposed antenna is a good candidate for WBAN applications.

A tapered cavity-backed flush-mountable dual mono-cone antenna is proposed. The proposed antenna consists of four main sections: a lower mono-cone, an upper mono-cone, novel feeding structures, and an exponentially tapered cavity. To obtain high-frequency band operation, the upper mono-cone excited by the feeding structures is located inside the lower mono-cone. The circular cavity used in the proposed antenna has a tapered wall for mitigating the deterioration of radiation performance. The proposed antenna has overall dimensions of 200 mm × 200 mm × 30 mm. The measured reflection coefficients (S-parameters) are below -10 dB from 1.43 GHz to 39.05 GHz (1:27.3). The measured radiation pattern has a quasi- omnidirectional characteristic in the operating frequency band.

A modified rectangular monopole ultra-wideband (UWB) antenna with penta notched frequency bands is presented. An inverted U shaped and slanted U-shaped on the radiating patch are inserted to achieve WiMAX and ARN bands rejection respectively, two mirrored summation Σ-shaped and four mirrored 5-shaped slots are inserted on the partial ground to achieve WLAN and X-band bands rejection respectively, finally rectangular shaped slot with partially open on the feed is inserted to achieve ITU-8 band rejection. The proposed antenna which was simulated has a compact size 30×35×1.6 m3. It is operated with impedance bandwidth 2.8-10.6 GHz at |S11| < −10 dB, that supported UWB bandwidth with filtering the five narrowbands that avoid the possible interference with them. The simulated resonant frequency for notched filters received 3.55, 4.55, 5.53, 7.45, 8.16 GHZ, for WiMAX, ARN, WLAN, X-Band, ITU-8 respectively. The proposed antenna is suitable for wireless communication such as mobile communication and internet of everything (IoE). Throughout this paper, CST-EM software package was used for the design implementation. Surface current distributions for all notched filters were investigated and shown that it is concentrated around the feeding point and the inserted notched slots proving that there is no radiation to the space due to maximum stored electromagnetic energy around each investigated notch slot, proving that the slots play a role of a quarter wavelength transformer which generates for each notched band, maximum gain, and radiation pattern are also investigated.

A frequency reconfigurable antenna is presented in this paper as a novel single port system gathering the functionalities of both underlay and interweave cognitive radio. This 25×30×0.8 mm3 system involves a wide slot antenna to cover the ultra wide band (UWB) range with resonating stubs that are used to prohibit/work-only-in specific bands within the UWB frequencies. Here, six positive intrinsic negative (PIN) diodes are used to decide the active sections of the antenna that leads to select its operation as UWB/filtering/multiband antenna. Diodes' configuration results in eight useful operation modes that include a scanning mode, four single band-notch modes and three dual band communication modes. The scanning mode covers the entire UWB range while one of the bands allocated for WiMax, Cband, WLAN or Xband is to be excluded in each of the band-notch modes. On the other hand, each communaication mode is able to work in one of the ranges that cover WiMax/Cband, Cband/WLAN or Xband/international telecommunication union (ITU). S11, realized gain, voltage standing wave ratio (VSWR) outcomes of this design that is simulated by computer simulation technology (CST) v.10 all confirms the proposed system's ability to work in the intended modes. Its novelity to work as interweave/underlay cognitive radio system, highly candidates this design to address many of the UWB communication issues related interference and multiband operation

A compact (27.5×16.5×0.8 mm3) co-planar waveguide fed printed ultra-wideband antenna operating in the impedance band of 1.75-10.3 GHz with two wide frequency notch bands at 2.2–3.9 GHz and 5.1–6 GHz, is introduced. Dual notch is achieved by inserting U-slot on the radiator and with inverted patch shaped downscaled parasitic load at the opposite end of feed line. Maximum antenna gain augmentation by about 5 dBi is achieved without changing the bandwidth, by incorporating a dual layer reflective frequency selective surface (FSS) of dimension 33×33×1.6 mm3 below the antenna. The antenna-FSS composite structure exhibits maximum radiation in the broadside direction with a peak gain of 9 dBi and an average radiation efficiency of more than 80% in the operating band. Antenna transfer function and group delay are experimentally studied in ground coupling mode of ground penetrating radar (GPR). Linear magnitude response of transfer function and consistent, flat group delay are achieved, that ensure minimal antenna dispersion and its ability for GPR application.

In this paper, an Ultra Wide Band antenna with reconfigurable filtering-characteristic is proposed to overcome interferences problems in the frequency range 3.1 GHz–10.7 GHz. With dimensions of 35 x 35 mm2, the structure is simple, low–cost and possesses an operating bandwidth from 3 GHz to 12 GHz. Besides, it is easy to reconfigure this antenna to filter one, two or three interferences, in which the filtering is achieved by three slots of half wavelength created in the geometry, while the reconfiguration is achieved through four PIN diodes used to control the three slot’s effect. Considering the filtering action, this antenna can switch between eight distinct operational modes, which is the highest number compared to previous works. Design and analysis of the proposed configuration are done by two simulation software which are CST and HFSS. The acceptable agreement between the results obtained by both simulations proves the realistic working performance of the proposed structure. The present antenna is suitable for UWB communication applications, particularly; the which are suffering from interference issues with WiMAX 3.3 GHz–3.7 GHz, WLAN 5 GHz–5.3 GHz or ITU band 8 GHz–8.4 GHz. DOI: http://dx.doi.org/10.5755/j01.eie.24.5.21849

In this paper, the recent progress on sinuous antennas is detailed, focusing the attention on the antenna geometry, dielectric structure, and miniaturization techniques. In the first part, we introduce the basic principles of the frequency-independent antenna, in particular the self-complementary and log-periodic geometries, as well as the antenna geometries, all characterized in terms of angles. The operating principles, main advantages, system design considerations, limits, and challenges of conventional sinuous antennas are illustrated. Second, we describe some technical solutions aimed to ensure the optimal trade-off between antenna size and radiation behavior. To this aim, some special modification of the antenna geometry based on the meandering as well as on the loading with dielectric structures are presented. Moreover, the cavity backing technique is explained in detail as a method to achieve unidirectional radiation. Third, we present a new class of supershaped sinuous antenna based on a suitable merge of the 2D superformula and the sinuous curve. The effect of the free parameters change on the antenna arm geometry as well as the performance improvement in terms of directivity, beam stability, beam angle, gain, and radiating efficiency are highlighted.

In this paper, CPW-Fed ultra wideband (UWB) planar monopole antenna (PMA) loaded by double elliptical split ring resonators (ESRRs) for double band-notch characteristics is introduced and examined. Two different ESRRs with different dimensions are printed in the antenna backside to notch two different frequencies. The ESRRs are also rotated and the corresponding return loss effect is examined. Different notch frequencies can be obtained by varying the ESRRs, dimensions. Two single SRRs are used to notch two frequencies instead of using dual SRR pairs. Two notch frequencies at 5.2 GHz and 6.9 GHz has been obtained to notch WLAN and C-band wireless applications, respectively. A directive radiation pattern in E-plane and omnidirectional radiation patterns in the H-plane could be observed. Also the gain is suppressed in the notch frequencies. The group delay is nearly stable in the UWB frequency range, except at the notch frequencies, which is distorted sharply. So, the proposed antenna is a good candidate for the modern UWB systems. Finite element method FEM and finite integration technique FIT are used to simulate the proposed structures through the usage of Ansys HFSS and CST MWS. Very good agreement between both results has been obtained.

In this paper, a systematic design procedure of a compact and broadband circularly polarized (CP) antenna is proposed. The antenna is first designed with a C-shaped monopole, and then a C-shaped slotted patch is utilized to produce CP radiation in the lower frequency band. Thus, the antenna's overall CP bandwidth (BW) is significantly increased. In addition, unlike the conventional method in which the operation is verified by the simulated surface current distribution, characteristic mode analysis (CMA) is carried out to give more insight into different modes on the antenna and generation of circular polarization. The CMA also helps to realize a structural optimization and identify an efficient feed location. The optimized antenna prototype with a compact size of 0.29λ0 × 0.29λ0 × 0.01λ0 (λ0 is the minimum wavelength at the minimum operation frequency) achieves a usable 10-dB reflection coefficient and 3-dB axial ratio fractional BW of 91% (2.1-5.6 GHz). The antenna realized broadside gain varies from 1.5 to 3.2 dBic within this measured overlapped BW.

A novel hammer-shaped UWB printed antenna with triple notched stop bands is presented and fabricated on FR-4 substrate with size of 40×40×1.6 mm3. The proposed antenna is composed of hammer-shaped patch with C-shaped slot, U-shaped slot on feed line, and inverted stepped notch and bevel edges with pair of L-shaped slots in partial ground plane. The fabricated antenna is tested and obtained impedance bandwidth 2.89 ̶ 11.6 GHz with three notched stop bands 3.15 ̶ 3.7 GHz, 5.45 ̶ 6.8 GHz, and 7.5 ̶ 8.8 GHz, for radiolocation system (RLS), wireless local area networks (WLAN), and X-band satellite communication system (XSCS) bands, respectively. Moreover, the antenna result shows omnidirectional radiation pattern, average gain of 3.10 dBi over the whole UWB band except at the notched frequency bands.

In this paper a multifunctional antenna is presented which offers an ultra-wideband (UWB) operation, an UWB operation with two switchable notches and reconfigurable dual-band operation for WiMAX and WLAN applications, respectively. Total seven functions/states could be achieved from a single antenna using an electronic switching. The antenna uses dual slots on the ground plane to provide a wide bandwidth, ranging from 3.1 GHz to 10.6 GHz. U-Shaped slot and C-Shaped printed strip in the ground are used to generate two notches at 3.6 GHz(WiMAX) and 5.2 GHz (WLAN/ WiFi) bands, respectively. Moreover, four parasitic strips are added in the feed side to make antenna functional at either3.6 GHz or 5.2 GHz or both. Total Five PIN diodes are required to obtain seven operations from the proposed antenna. Seven structures are fabricated and measured to verify the seven states and results are found in good agreement with estimated results obtained from the simulation.

This paper presents the design and realization of a compact ultra-wideband (UWB) antenna with a rectangular notch wireless area network (WLAN) band that has controllable notched bandwidth and center frequency. The UWB characteristics of the antenna are achieved by truncating the lower ends of the rectangular microstrip patch, and the notch characteristics are obtained by using electromagnetic bandgap (EBG) structures. EBGs consist of two rectangular metallic conductors loaded on the back of the radiator, which is connected to the patch by shorting pins. A rectangular notch at the WLAN band with high selectivity is realized by tuning the individual resonant frequencies of the EBGs and merging them. Furthermore, the results show that the bandwidth and frequency of the rectangular notch band could be controlled according to the on-demand rejection band applications. In the demonstration, the rectangular notch band was shifted to X-band satellite communication by tuning the EBG parameters. The simulated and measured results show that the proposed antenna has an operational bandwidth from 3.1&ndash, 12.5 GHz for |S11| &lt, 10 with a rectangular notch band from 5&ndash, 6 GHz, thus rejecting WLAN band signals. The antenna also has additional advantages: the overall size of the compact antenna is 16 &times, 25 &times, 1.52 mm3 and it has stable gain and radiation patterns.

In this manuscript, the design of a dualport/dual-polarized slot antenna with improved gaincharacteristic is proposed for ultra-wideband (UWB)applications. The antenna design contains a diamond-ring slotradiator fed by two independently arrow-shaped microstripfeeding lines which can exhibit a polarization diversitycharacteristic. A low-cost FR-4 dielectric (= 4.4, = 0.02) isused as the substrate. In order to increase the gaincharacteristic of the antenna a 10×10 single-layer frequencyselective surface (FSS) is employed below the dual-polarizedslot antenna. The unit cell of the proposed FSS contains asquare-ring radiator with a protruded circular-ring strip. Amaximum gain of 9 dBi with less than 3 dB variation isobtained over the UWB frequency band. The characteristicsof the dual-polarized UWB slot antenna with and without theFSS were examined using simulations and good simulationresults have been obtained.

In this paper, a new approach to the design of an UWB monopole antenna with dual band-notched characteristics is presented. The antenna has the form of an elliptical monopole over a ground plane having an elliptical slot to achieve the UWB. The dual-band notch function is created by inserting a U-shaped and a C-shaped slots on the radiating patch, thus no extra size is needed. The proposed antenna shows a good omnidirectional radiation pattern across the band from 3.2 to more than 14 GHz. The dual band-rejection is for 4.88-5.79GHz centered at 5.4GHz and 7.21-8.46 GHz centered at 7.8 GHz. The antenna prototype using the FR-4 substrate with εr=4.3 has a compact size of 25mm×25 mm ×1.45mm. The fabricated prototype showed experimental results comparable to those obtained from the simulations.

A novel reconfigurable filter antenna with three ports for three dependent switchable states for impulse radio-ultrawideband (IR-UWB)/wireless local area network (WLAN)/worldwide interoperability for microwave access (WiMAX) applications is presented in this paper. Three positive-intrinsic-negative diodes, controlled by direct current, are employed to realize frequency reconfiguration of one ultra-wideband state and two narrowband states (2.4 GHz and 3.5 GHz). The time domain characteristic of the proposed antenna in the ultra-wideband state is studied, because of the features of the IR-UWB system. The time domain analysis shows that the reconfigurable filtering antenna in the wideband state performs similarly to the original UWB antenna. The compact size, low cost, and expanded reconfigurable filtering features make it suitable for IR-UWB systems that are integrated with WLAN/WiMAX communications.

Publisher's version (útgefin grein), In this article, a generalized sequential domain patching (GSDP) method for efficient multi-objective optimization based on electromagnetics (EM) simulation is proposed. The GSDP method allowing fast searching for Pareto fronts for two and three objectives is elaborated in detail in this paper. The GSDP method is compared with the NSGA-II method using multi-objective problems in the DTLZ series, and the results show the GSDP method saved computational cost by more than 85% compared to NSGA-II method. A diversity comparison indicator (DCI) is used to evaluate approximate Pareto fronts. The comparison results show the diversity performance of GSDP is better than that of NSGA-II in most cases. We demonstrate the proposed GSDP method using a practical multi-objective design example of EM-based UWB antenna for IoT applications., National Natural Science Foundation of China Grant, 61471258 and by Science & Technology Innovation Committee of Shenzhen Municipality Grant, KQJSCX20170328153625183., "Peer Reviewed"

International audience; This article presents the miniaturization of a UWB planar monopole antenna covering the VHF band through the use of low loss Magneto-Dielectric Materials (MDM). By using slots in the antenna structure, the dimensions and position of the MDM have been optimized to reduce the amount of MDM required to obtain an optimum miniaturization rate. This new monopole structure shows a miniaturization rate of 60% by covering about only 5% of the antenna surface area.