Search

This paper proposes the design of a T-shaped antenna that resonates at 3.6 GHz, suitable for 5G small-cell technology. An EBG structure consists of four unit cells, each comprising rectangular strips. The periodic structure is combined with the antenna design, and performance enhancement in terms of gain and impedance bandwidth is observed. The gain of the antenna without periodic structure is 3.78 dBi, whereas with periodic structure it is enhanced by 1.1 dB and is noted as 4.8 dBi. The antenna dimensions are 38 mm × 37 mm × 3 mm. Also, the measured impedance bandwidth of the antenna structure without periodic structure is 60 MHz. In contrast, the proposed prototype antenna backed with an EBG structure provides the measured impedance bandwidth of 80 MHz (3.49 GHz to 3.57 GHz). [ABSTRACT FROM AUTHOR]

ABSTRACT A novel superstrate‐based Vivaldi antenna design characterized by high‐gain and wideband performance is presented. The proposed design configuration features a Vivaldi antenna positioned between high dielectric superstrate (Rogers 6010, εr = 10.2) with copper etched off on both sides and an FR4 substrate that has copper etched on one side only. The introduction of a high permittivity dielectric material above and a reflector below the Vivaldi antenna enables favorable resonance conditions for achieving high‐gain operation. The measured antenna exhibits a peak gain of 17 dBi at 10 GHz, covering an operating frequency range of 6–20 GHz. It also features a narrow half‐power beamwidth and low side lobe level radiation patterns. Unlike existing studies, which rely on metamaterials, electromagnetic bandgap structures, and frequency selective surfaces for gain enhancement, our design employs high‐dielectric constant superstrates. This approach increased the antenna's peak gain by 10 dB. Also, the proposed configuration act as a radome protecting the antenna from Environment. [ABSTRACT FROM AUTHOR]

Summary A wearable dual‐band dual‐polarized fabric antenna is screen printed on a cotton polyester substrate to operate at the industrial scientific and medical band at 2.45 GHz and wireless local area network at 5.2 GHz. A rectangular slot with a pair of L‐shaped branches are used to excite dual bands. The rectangular slot is used to achieve lower band resonance at 2.45 GHz with linear polarization, and an L‐shaped branch with a stub is used to obtain the circular polarization at 5.2 GHz. A 3 × 3 electromagnetic bandgap (EBG) structure is enabled behind the antenna to minimize the back radiation and specific absorption rate (SAR). The antenna provides a measured impedance bandwidth (BW) of 25% from 2.1 to 2.7 GHz (600 MHz), and 18% from 4.5 to 5.7 GHz (1.2 GHz), respectively. The antenna also has a 3‐dB axial ratio BW of 15% from 4.6 to 5.35 GHz (750 MHz). The antenna exhibits a measured gain of 5.1 dB at 5.2 GHz and 6.4 dB at 2.45 GHz. The SAR is validated by using a CST (computer simulation technology) voxel human body model and found to be 0.0949 and 0.127 W/kg for 1 g tissue at 5.2 and 2.45 GHz, respectively. The dimension of the proposed EBG integrated antenna is (0.52 λ × 0.52 λ × 0.07 λ). The antenna and EBG structure are screen printed with silver conductive ink, which provides good conductivity, conformability, comfort, wearability, and being lightweight. [ABSTRACT FROM AUTHOR]

A compact triple‐band porous electromagnetic bandgap structure‐loaded coplanar‐waveguide‐fed wearable antenna is introduced for applications of wireless body area networks. The porous structure is aimed to create a stopband or bandgap in the electromagnetic spectrum and increase breathability. The holes in the bottom electromagnetic bandgap surface increase the inductance, which in turn increases the bandwidth. The final design resonates at three bands with impedance bandwidths of 264 MHz, 100 MHz, and 153 MHz and maximum gains of 2.18 dBi, 6.75 dBi, and 9.50 dBi at 2.45 GHz, 3.5 GHz, and 5.5 GHz, respectively. In addition, measurements indicate that the proposed design can be deformed up to certain curvature and withstand human tissue loading. Moreover, the specific absorption rate remains within safe levels for humans. Therefore, the proposed antenna can suitably operate in the industrial, scientific, and medical, Bluetooth, Wi‐Fi, and WiMAX bands for potential application to wireless body area networks. [ABSTRACT FROM AUTHOR]

In this letter, a low‐cost and easy‐to‐embed 7‐bit 360° phase shifter with transitions is presented for applications to beamforming in the large‐scale phased array. In the proposed 360° phase shifter, the topology of the reflection‐type phase shifter (RTPS) is employed, composed of a 3‐dB branchline coupler terminated with two tunable parallel L–C loads. First, a two‐step phase extraction process for RTPS is applied to design the RTPS rapidly with competitive performance, including 360° phase range and low insertion loss. A huge amount of parameter sweep is reduced in the design and test. Meanwhile, the parameter of inductors in the tunable loads is investigated effectively, to achieve the minimal phase step. Second, aiming at the enhanced performance of beamforming and improved flexibility of integration, the stripline is adopted in the design of the phase shifter, avoiding the interference on antenna radiation effectively. To facilitate the integration with antenna and radio frequency connectors of the input and output signals, a stripline‐to‐microstrip line transition with electromagnetic bandgap structures is adopted. By this means, the complexity and cost of fabrication are decreased. Finally, fabricated in the low‐cost printed circuit board technology, our proof‐of‐concept design operated from 2.4 to 2.5 GHz is measured and achieves a 386.8° phase shift range with an insertion loss of 2.21 ± 0.82 dB at 2.45 GHz. [ABSTRACT FROM AUTHOR]

Summary: A dual‐band, wearable coplanar microstrip patch antenna (CPW) integrated with electromagnetic bandgap structure (EBG) to operate dual wireless bands at 2.48 GHz industrial, scientific, and medical band (ISM) and 5.2 GHz WLAN. The proposed textile wearable antenna and EBG structure are screen‐printed using silver conductive ink on the cotton polyester substrate (εr = 1.6) for flexible wearable applications. A 3 × 3 EBG array is realized by a concentric square patch surrounded by the annular square ring to reduce back radiation and increase the forward gain and front‐back ratio. The proposed EBG‐backed antenna, compared with the conventional CPW‐fed antenna, improves forward gain from 2.18 to 6.59 dB at 2.48 GHz and 3.5 to 7.03 dB at 5.2 GHz. Moreover, the EBG array is used to isolate the human body from the antenna and reduces the specific absorption rate (SAR). The antenna is performed with a human phantom tissue model, which exhibits a specific absorption rate of 0.12 W/kg, and 0.260 W/kg for 1 g tissue at 2.48 GHz and 5.2 GHz, respectively. [ABSTRACT FROM AUTHOR]

This letter presents a multifunctionality reconfigurable substrate-integrated waveguide (SIW) filter embedded in a microstrip line. The proposed filter used an electromagnetic bandgap structure (EBG) to compact the size and improve the electromagnetic features. The SIW filter consists of a three-cell EBG with metallic circular-shaped connected to the ground through cylindrical vias. Firstly, the base SIW structure offers a wide passband filtering response, and then, to obtain selective passband, wide band rejection, and controllable resonance frequencies, a three-cell EBG along with four diodes has been attached. The filter is designed and printed on a Rogers 4003 substrate with a thickness of 1 mm and is experimentally validated for functionalities operated at three modes with an average 3 dB bandwidth of 115 MHz in each frequency. In addition to that, two transmission zeros (TZ) have been produced in the upper band frequency. The filter's response is also tunable by turning the diode off or on and changing the main parameters of EBG, the gab, and the position between cells. The study explores resonance frequency alterations in a three-state system of on/off. By eliminating or diminishing specific modes, and incorporating diodes, distinct resonance behaviors are observed. Moreover, shifting frequency resonance in a multiparameter system has been investigated. Increasing B1 induces a significant shift to lower values, while an increase in D1 leads to a decrease in the first and second resonance frequencies and an upward shift in the third. The designed filter has been fabricated and tested to compare and confirm simulated responses. Simulation and measurement results are in good agreement. The S-parameters of measured results gained a good response (>15 dB) within the passbands and stopbands and an insertion loss of 1.5 dB suitable for 5G and Wi-Fi systems. [ABSTRACT FROM AUTHOR]

A screen-printed wearable coplanar waveguide (CPW) fed semi-octagonal shaped antenna is developed on a denim textile substrate to resonate at 2.45 GHz for wireless medical body area network communications. The antenna is integrated with a circular ring-type electromagnetic bandgap structure (EBG) to mitigate performance degradation due to the high permittivity of the tissue model when it works on body conditions. The CPW antenna and EBG surfaces are fabricated using the screen-printing method, which provides good conformability, good wearable comfortability, and light weight. The proposed EBG integrated antenna has dimensions of 0.66λ × 0.66λ × 0.056λ and an impedance bandwidth of 13% (2.3-2.62 GHz) with a gain of 6.7 dB. The specific absorption rates (SARs) of the antenna are 0.309 W/kg and 0.14 W/kg for 1 g and 10 g of tissue, respectively, which are within the wearable safety limits. Thus, the fabricated prototype antenna is suitable for wearable WBAN and MBAN applications. [ABSTRACT FROM AUTHOR]

In this paper, a dual‐polarized multibeam antenna in X‐band is designed and physically fabricated using a parabolic reflector. The antenna consists of a feed array and a metal reflector. A dual‐polarized microstrip antenna array combining two design approaches, T‐coupled feed and defective ground structure, is adopted as the feed array to improve polarization isolation. In addition, the electromagnetic bandgap structure is loaded between the antenna units to reduce the mutual coupling and improve the isolation between the units. A nine element of the highly‐isolated dual‐polarized microstrip antenna array is designed to be placed on the focal plane of the parabolic reflector as the feed, and the beam deflection is realized by using the lateral defocus effect of the parabolic plane, which can finally realize nine single beams covering a 30° scanning range in both horizontal and vertical polarization modes. Based on the scanning state of multiple point beams, this paper uses the Fourier series for beam assignment to form a flat‐top beam with a wide scanning angle. The application of the antenna with two operating modes of wide beam and multibeam to navigational satellite systems can greatly improve the accuracy and efficiency of navigation. [ABSTRACT FROM AUTHOR]

A bandwidth enhanced multilayer Electromagnetic Band Gap (EBG) structure to reduce the simultaneous switching noise (SSN) in high frequency operating circuits, which useful for the satellite communication application, is presented in this paper. A proposed stack structure is mathematically analyzed by the dispersion method and transmission matrix method. Simulation results show good mitigation of SSN in scattering parameters and signal integrity in terms of eye diagrams. We have also checked for power integrity analysis using self-impedance. The proposed structure gives a good SSN suppression at -30 dB from 817 MHz to 26.32 GHz, around 25.50 GHz bandwidth and also reduces the cavity mode resonance within the stopband range. The proposed multilayer structure is compared with planar EBG plane and reference board. It is also compared with published results. [ABSTRACT FROM AUTHOR]

Electromagnetic Bandgap (EBG) structures that exhibit various performances, such as preventing the electromagnetic wave propagation and reflecting an incident wave within the stopband, have unique electromagnetic characterization. Due to this reason, accurate analysis and design of the EBG structures are crucial to enhance the integrated system performance. This paper concentrates on the characterization of some planar EBGs using the Auxiliary Functions of Generalized Scattering Matrix (AFGSM) methods, with particular importance on an in- depth consideration of its bandgaps. The AFGSM method is applied to the planar EBG structures in the literature for the first time. The well-known kinds (symmetric and asymmetric cases) of mushroom type and multilayer EBG structures are considered to verify the presented method. Analysis results are compared with the Conventional Eigenvalue Equation (C-EIV) and the Generalized Scattering Matrix based Eigenvalue Equation (GSM-EIV) methods. Low computation load and accurate results are obtained to analyze the planar EBG structures with the AFGSM method due to using transmission line model. In addition, a design methodology is proposed for a chosen planar EBG structure using the AFGSM methods. Geometrical parameters of interested EBG problems are determined for acquiring the stopband frequency region of interest using the scattering parameters of unit cell configuration. The mushroom EBG model along one and two-dimensional axes is used in an antenna application to decrease mutual coupling between antenna elements. Three different scenarios are simulated in the HFSS electromagnetic simulation design environment to understand the effect of mutual coupling reduction in the antenna problem of the designed EBG structure via the AFGSM method. All designed antennas are manufactured, and the measurement results are in good agreement with the simulation results. The measurement results of the fabricated antenna application example including designed EBG using the proposed AFGSM method are compared with the existing similar problems with the same and different EBG models. It has been demonstrated that bandgap analysis, design of the planar EBG structures and integration of considered EBG model to a design application can be accurately and quickly achieved with the given methodology using the AFGSM method.

In this paper, a ring patch antenna with 1 GHz of bandwidth and three resonances is designed for the RF energy harvesting application. Two complementary split-ring resonators (CSRR) is etched out from the patch, designed at 6.8 GHz, near feed to enhance the bandwidth from 267 MHz to 1 GHz. Due to the introduction of CSRR, two additional resonances at 6.4 and 7.4 GHz are obtained with gain 5.5 and 0.2 dB respectively. The gains at 6.8 and 7.4 GHz are enhanced to 8.3 and 2 dB respectively by cascaded circular mushroom electromagnetic bandgap structures (EBGs) with circular symmetry designed around the antenna. This ring patch antenna with cascaded EBG is integrated with a rectifier circuit based on voltage doubler topology (rectenna). The results of the rectenna show that, for an input power of 7 dBm to the rectifier circuit, a DC output voltage of 1.2 V with a power conversion efficiency of 40% is achieved. [ABSTRACT FROM AUTHOR]

A deep neural network (DNN)-based method is proposed for the fast synthesis of a high-dimensional electromagnetic bandgap structure (HD-EBG) suppressing the power/ground noise in high-speed packages and printed circuit boards (PCBs). In recent EBG structures, a highly flexible design with high dimensionality is required, which is challenging to rapidly achieve an optimal solution. The proposed synthesis method is developed to solve this issue efficiently. The DNN hyperparameter optimization (HPO) associated with the HD-EBG structure is devised using the orthogonal array of the Taguchi method. By using this approach, the search space for HPO is reduced. For the efficient synthesis of the HD-EBG structure, an inverse modeling approach based on a DNN forward model and genetic algorithm optimization is proposed. The proposed DNN inverse modeling (DIM) is applied to two design examples where the HD-EBG structures with a constant fractional bandwidth and stopband bandwidth extension are synthesized. In the demonstration cases, the proposed DIM achieves the fast and accurate synthesis of the HD-EBG structures compared to the conventional method. With the proposed method, the synthesis time is maximally reduced up to 99.8% compared to conventional synthesis based on the forward model of full-wave simulation. [ABSTRACT FROM AUTHOR]

In this study, a method of combining graphite structure and electromagnetic bandgap to reduce the mutual coupling of electromagnetic waves in array antennas is proposed. This structure is designed according to the special physical properties of graphite for the emission of electromagnetic waves, transmission theory, as well as the inductance and capacitive properties of the electromagnetic bandgap structure to dissipate surface currents. The proposed multi-input and multi-output (MIMO) antenna was designed and measured with two radiating elements on a substrate. The results show that the effects of mutual coupling between radiating elements are reduced by 30 dB at the operating frequency of 3.34 GHz. By placing this structure, all antenna components, including gain, patterns, and radiation efficiency, are improved. Calculations showed that antenna components: gain and antenna radiation efficiency increased by 1.2 dB and nearly 24%, respectively. To confirm the good performance of the graphite structure, all components of the MIMO antenna, including the envelope correlation coefficient, diversity gain, mean effective gain, channel capacity loss, and total active reflection coefficient, were investigated. The results showed the desired values, which indicate the very good performance of the graphite structure on all the basic characteristics of the antenna. [ABSTRACT FROM AUTHOR]

In this paper, a simultaneous application of geometric modification on patch elements and electromagnetic band gap (EBG) electromagnetic bandgap structures (hybrid method) has been suggested for 3.5 GHz wireless communication applications, to minimize the mutual coupling between radiating elements of microstrip array antennas. The suggested EBG slotted structure is composed of a one square ring and three squares placed on Rogers RO3010 having 10.2 and h=1.27 mm which presents respectively its dielectric constant and thickness. In this approach, the patch elements are geometrically modified, while also employing EBG structures, formed by four EBG cells, placed between the array elements at a near distance. The modification of the geometry of the antenna and the introduction of EBG reduces the mutual coupling of an array antenna with approximately 33 dB on the one hand and improves the antenna gain by approximately 0.43 dB on the other hand. Initially, slots are introduced in the patch geometry and then four EBG unit cells are inserted between two patches, operating at 3.5 GHz. The antenna array design parameters were optimized. [ABSTRACT FROM AUTHOR]

This work demonstrates the design of a single band Electromagnetic Band Gap (EBG) antenna by employing an open stub EBG microstrip of a patch antenna for better achievements in terms of its performance to be utilized in a reconfigurable harvester to operate over a wide input power range. The EBG antenna has been used to gather RF energy and a FET-transistor has been obtainable to determine and control the power flow with the intention to operate at the same time for a different level of input power. The measured data of the EBG antenna shows a directivity of 8.52 dBi, a gain of 7.18 dBi, a return loss of -27 dB with a radiation efficiency of 84.3%, showing a clear enhancement in directivity, peak realized gain, and radiation efficiency by 41.76%, 25.61%, and 17.12% respectively compared with a regular reference antenna; without utilized the EBG structure. Moreover, the harvester design accomplishes 40% of RF-DC power conversion efficiency over a wide dynamic input power range from -15 to 27 dBm, and its peak is around 78%. The harvester is designed to work at the ISM band for 915 MHz and is suitable for Wireless Power Transfer (WPT) uses. [ABSTRACT FROM AUTHOR]

The cognitive radio (CR) opens new paradigms of opportunistic utilization of unused frequency spectrum through spectrum sharing. Dynamic spectrum access (DSA) provides an effective solution to channel congestion with the help of software-defined radio in cognitive radio networks (CRN). Software defined radio (SDR) offers manipulative wide spectrum sensing and reconfigurable transmission properties between licensed primary user (PU) and unlicensed secondary user (SU). The opportunistic spectrum sharing elicits the need for hardware compatibility from a common radiating antenna for extra-large band spectrum scanning. This paper proposes a novel compact antenna for wide spectrum sensing to utilize vacant channel opportunity in wireless cognitive radio sensor network (WCRSN). The antenna design comprises the combinational effects of fractal slots and electromagnetic bandgap structure on compact FR4 substrate 12 × 18 × 1.6 mm2. The circular polarization improves the feasibility of antenna for orientation-free scanning of spectrum through corner truncation. The novel antenna design exhibits large measured impedance bandwidth from 0.79 to 12.0 GHz compatible with Zigbee, Bluetooth, GPS, GSM, LoRa, WiFi and other UWB applications. The antenna offers average gain 2.59 dBi over entire operating frequency range and validates compatibility for spectrum sensing in WCRSN as per FCC standards. [ABSTRACT FROM AUTHOR]

This paper investigates a trapezoidal Monopole Patch Antenna (MPA) with an Ultra-Wideband (UWB) characteristic and a dual-stage notched band at fifth generation (5G) and Wireless Local-Area Network (WLAN) bands. The 5G band is notched by inserting a U-shaped slot on the trapezoidal UWB MPA. The WLAN band is notched using five-square metallicconductor Electromagnetic Bandgap (EBG) patches that are installed on the surface of the backside of the radiating patch and attached to the ground plane via a shorting pin. The small, proposed antenna is built upon an FR4 substrate substance, having dielectric comparative permittivity εr= 4.7, and fed by a 50O coplanar waveguide. The antenna's size is 32×42.90×0.8 mm3. The simulated results show that the antenna has an operating frequency range of 2.39-14.72 GHz for |S11|<-10 rejecting WLAN (5.15-5.825 GHz), as well as sub-6 GHz 5G (3.4-3.9 GHz) great-selectivity signals. A higher gain obtained by the UWB antenna is 6.4 dBi, while a sharp decrease occurs in the rejected bands, reaching -8.29 dBi. This study also employs the Orbital Angular Momentum (OAM) technique. However, OAM waves are generated using eight trapezoidal UWB MPAs. Creating notches reduces the interference problem in UWB frequencies, and merging the UWB with the OAM technique allows the OAM to operate on many frequencies. Moreover, notches can be generated for specific frequencies inside the UWB bands. These techniques, trapezoidal UWB MPA and OAM wave generation, can significantly increase the spectrum range and improve the spectrum efficiency in wireless communications. [ABSTRACT FROM AUTHOR]

This article presents a miniaturized wide-angle scanning phased array for fifth-generation (5G) application. A subarray of two closely packed patch antennas on electromagnetic bandgap structure (EBG) ground with the operating bandwidth of 26–29 GHz is used as the basic module of the linear array, which contains four equally spaced subarrays. The existence of the EBG ground enables the array to be compact in size (3.2 × 0.6 × 0.12λL3), yet the mutual coupling between each element can reach to more than 22 dB within the whole band of interest. The EBG structures also contribute to the wide element radiation pattern of the aperiodic array and consequently the wide scanning angle performance of the array. The range of the main beam scan with EBG structure can reach from −70° to 70° with more than 6 dB side lobe levels (SLLs) at 26.5 GHz with 3 dBi scanning gain loss. This proposed method enabling the array to be compact and wide in scanning angle is very attractive for 5G mobile terminal applications. [ABSTRACT FROM AUTHOR]

This article focused on broadening the azimuth plane scanning range of surface-mounted linear arrays. First, 14 kinds of basic radiation models were theoretically analyzed, and the basic model with a 180° covered main lobe was pointed out. Afterward, a wide-beam surface-mounted antenna was designed using an in-phase-reflection electromagnetic bandgap structure based on the selected element model. Finally, an azimuth plane wide-angle scanning linear array with wide-beam surface-mounted elements was arranged, decoupled, and evaluated. This array can scan its beam in the range of 90° ± 85° in the azimuth plane with a 3 dB gain fluctuation, which verified the effectiveness of the proposed theoretical model. [ABSTRACT FROM AUTHOR]

We propose a polarization-twisting metasurface antenna (PTMA) to generate the dual-band dual-circularly polarized (CP) radiation by integrating a dual-linear-to-circular polarization converter (DLCPC) with a linear polarization conversion metasurface (LPCM) in the Ku-band. The DLCPC possesses the functionality of polarization selection and is capable of transforming the linearly polarized (LP) waves into right hand CP (RHCP) waves in low-frequency (LF) and left hand CP (LHCP) waves in high frequency (HF). Based on the DLCPC, the dual-band dual-CP PTMA is designed and fabricated, and then, the measured results indicate that the PTMA is capable of realizing the RHCP radiation in LF and the LHCP radiation in HF. In the meanwhile, the common bandwidths of −1.5 dB gains and 3 dB axial ratios are 12.25–12.95 and 14.00–14.55 GHz, respectively. Our design, by integrating the DLCPC and LPCM to construct the dual-band dual-CP PTMA, should, thus, pave the way for building up more efficient wireless communication systems with the requirement of different CPs as the receiver and the transmitter at downlink and uplink in the Ku-band. [ABSTRACT FROM AUTHOR]

Software-defined radio (SDR) deals with the opportunistic detection and allocation of the radio frequency (RF) signals in the cognitive radio network (CRN). The opportunistic spectrum use between primary licenced and secondary unlicensed user depends upon the adequate detection of the spectrum hole. This paper presents a design of a smart compact wideband patch antenna for SDR in cognitive radios. The fractal slot antenna with electromagnetic bandgap structure is designed on 12 × 18 mm2 FR4 substrate as a primary perception module in the cognitive radio sensor network. The wide operating range of antenna 0.68–12.1 GHz is highly compatible with adaptive learning of SDR to deal with dynamic spectrum variation over a large bandwidth. The antenna exhibits high radiation efficiency with consideration of tangential losses of FR4 and sustainable gain 2.5 dBi over the complete impedance bandwidth. The proposed five-layered ANN-ML supervised SDR comprises multispectral resolution via coefficient estimation for primary and secondary user and elicits high throughput of proposed antenna during white space spectrum sensing. The data analytics for ANN-ML has modelled on Python 3.0 IDE and the results are validated to justify the candidature of the antenna for wideband sensing as per the Federal Communications Commission standards for CRN. [ABSTRACT FROM AUTHOR]

In this study, power/ground noise suppression structures were designed based on a proposed dispersion analysis for packages and interposers with low-loss substrates. Low-loss substrates are suitable for maintaining signal integrity (SI) of high-speed channels operating at high data rates. However, when the power/ground noise is generated in the power delivery network (PDN), low-loss substrates cannot suppress the power/ground noise, thereby causing PDN-induced crosstalk and various power integrity (PI) issues. To solve these issues, noise suppression structures generating electromagnetic bandgap were proposed and designed. The mechanism of the proposed structures was examined based on a proposed dispersion analysis. The proposed structures were designed and fabricated in glass interposer test vehicles, and the effectiveness of the structures on power/ground noise suppression was experimentally validated by measuring the noise suppression band. The proposed dispersion analysis was also verified by comparing the derived noise stopband edges ( f L and f U ) with electromagnetic (EM) simulation and experimental results, and they all showed good agreement. Compared to EM simulation, the proposed method required smaller computational resources but showed good accuracy. Using the proposed dispersion analysis, various power/ground noise suppression bands were designed considering the applications and design rules of packages and interposers. With measurements and EM/circuit simulations, the effectiveness of the designed structure in maintaining SI/PI was verified. By adopting the designed structures, the noise transfer properties in the PDN were suppressed in the target suppression frequency band, which is key for PI design. Finally, it was verified that the proposed structures were capable of suppressing power/ground noise propagation in the PDN by analyzing PDN-induced crosstalk in the high-speed channel. [ABSTRACT FROM AUTHOR]

Propagation of a nanosecond microwave pulse through a photonic crystal placed into an X-band waveguide is investigated. The nanosecond pulse is produced via shortening of the microsecond microwave pulse by the plasma electromagnetic band gap structure, which is formed in the waveguide by microwave breakdown ignited discharges inside three neon-filled glass tubes. Measured delay time for nanosecond microwave pulse propagation through the photonic crystal is about 23 ns that is in good agreement with the value obtained by numerical simulation. This time delay value corresponds to the group velocity of microwave pulses in the photonic crystal vgr=0.11c, where c is the speed of light in vacuum. [ABSTRACT FROM AUTHOR]

The microwave-absorbing properties of a heterostructure consisting of an ordered monolayer of porous glassy carbon spheres were experimentally and theoretically investigated in the Ka-band (26-37GHz) frequency range. The electromagnetic response of such a "moth-eye"-like all-carbon metasurface at a normal incidence angle was modelled on the basis of long-wave approximation. Modelling parameters in the Ka-band were used to estimate and predict the absorption properties of monolayers in free space in the range 1-40 GHz. Experimental and theoretical results demonstrate that a metasurface based on porous glassy carbon spheres is an inert, lightweight, compact, and perfectly absorbing material for designing new effective microwave absorbers in various practically used frequency ranges. [ABSTRACT FROM AUTHOR]

This study presents a novel configuration of a cuboidal quad-port ultra-wideband multiple-input and multiple-output antenna with WLAN rejection characteristics. The designed antenna consists of four F-shaped elements backed by a partial ground plane. A 50 Ω microstrip line is used to feed the proposed structure. The geometry of the suggested antenna exhibits an overall size of 23 × 23 × 19 mm3, and the antenna produces an operational bandwidth of 7.6 GHz (3.1–10.7 GHz). The notched band characteristic at 5.4 GHz is accomplished by loading a pair of spiral electromagnetic bandgap structures over the ground plane. Besides this, other diversity features such as envelope correlation coefficient, and diversity gain are also evaluated. Furthermore, the proposed antenna system provides an isolation of −15 dB without using any decoupling structure. Therefore, to validate the reported design, a prototype is fabricated and characterized. The overall simulated performance is observed in very close agreement with it's measured counterpart. [ABSTRACT FROM AUTHOR]

(1) and (2) is calculated by the width of lines [[1]] (Note: I i SB I g i sb is the calculated guided wavelength at 1.50 GHz). HT ht Graph (1) HT ht Graph (2) To achieve the LC equivalent structure of the proposed elliptical resonators, new computed formulas (Eqs. Keywords: elliptical shaped resonator; LC equal structure; lowpass filter (LPF); output to input ratio; transmission zero; ultra-wide stopband EN elliptical shaped resonator LC equal structure lowpass filter (LPF) output to input ratio transmission zero ultra-wide stopband 247 254 8 05/09/22 20220601 NES 220601 1 Introduction Compact microstrip LPFs with ultra-wide stopband are extremely desirable for wireless and mobile communication systems to suppress unwanted high frequency harmonics. [Extracted from the article]

A broadband coplanar‐to‐rectangular waveguide transition using contactless electromagnetic bandgap (EBG) structure in the form of interdigital‐pin bed of nails has been introduced in this paper. The electromagnetic (EM) wave propagates from the CPW, and then radiates from the probe into the WR4. The rectangular patch is adopted as the probe to accomplish a broadband performance without an impedance transformer. At the same time, CPW to rectangular waveguide (RW) directly transition without EBG unit also has been designed and the simulated results show the transmission performance has low tolerance to air gap. The interdigital‐pin EBG structure is added to the machining splitter of the RW which is no need for strict electrical contact and is not harmful for transition performance. The greatest advantage of the interdigital‐pin lattice has a significant pin gap increase and is easy to fabricate for millimeter‐wave (mm‐Wave) and terahertz (THz) applications. The back‐to‐back prototype is designed, fabricated and measured. The measured |S11| is better than −10 dB over 170–260 GHz, covering a bandwidth of 41.8%. [ABSTRACT FROM AUTHOR]

A multiconductor transmission-line (MTL) model is proposed with which to model the uniplanar compact electromagnetic bandgap structure (UC-EBG). The model is based on a 2-D arrangement of metamaterial-based electromagnetic bandgap structures (MTM-EBGs), with a central node region. The branches of this structure are modeled as conductor-backed coplanar waveguide segments with integrated series capacitors, while the node region is modeled as a grid of microstrip (MS) lines with suitably augmented propagation velocities. The dispersion properties of the canonical UC-EBG unit cell are simulated in Ansys HFSS and compared with those of an equivalent simulation model based on a 2-D arrangement of weakly loaded MTM-EBGs, as well as similar data produced by the MTL equivalent-circuit model, which are all found to be in agreement. It is then shown that additional capacitive loading allows for substantial miniaturization, a regime in which even better agreement is produced between the equivalent circuit model’s dispersion data and the data produced by an equivalent HFSS model. Using these data, the Bloch modes of this structure are analyzed in detail. Thus, the MTL perspective offers a recipe for producing highly miniaturized UC-EBG unit cells that may be successfully integrated into printed circuit board (PCB) systems for applications in parallel-plate noise and surface-wave (SW) mode suppression, among others. [ABSTRACT FROM AUTHOR]

High gain antennas are highly desirable for long-range wireless communication systems. In this paper, a compact, low profile, and high gain dielectric resonator antenna is proposed, fabricated, experimentally tested, and verified. The proposed antenna system has a cylindrical dielectric resonator antenna with a height of 9 mm and a radius of 6.35 mm as a radiating element. The proposed dielectric resonator antenna is sourced with a slot while the slot is excited with a rectangular microstrip transmission line. The microstrip transmission line is designed for a 50 impedance to provide maximum power to the slot. As a result, the proposed antenna operates at 5.15 GHz with a 10-dB absolute bandwidth of 430 MHz (4.98 - 5.41 GHz). It is important to mention that the gain of the dielectric resonator antenna is enhanced by the introduction of an electromagnetic bandgap (EBG) structure. In fact, EBG units are placed below the antenna, which enhances the realized peak gain from 5.32 dBi to 8.36 dBi at 5.15 GHz. More specifically, a gain enhancement of 3.04 dB is observed with the introduction of the EBG array. This antenna has several good features such as high gain, compact size, large bandwidth, and lower losses which make it a suitable choice for long-range wireless communication systems. [ABSTRACT FROM AUTHOR]

This paper proposes Inductive Enhanced-Electromagnetic Bandgap (IE-EBG) structure to suppress the Ground Bounce Noise (GBN) for high-speed digital system applications. The GBN excited between the power and ground plane pair could be a source of interference to the adjacent analog IC's on the same PCB (or) nearby devices because of radiated emission from the PCB edges. Hence, it must be suppressed at the PCB level. The proposed two-dimensional IE-EBG patterned power plane suppressed the GBN effectively over a broad frequency range. The four unit-cell IE-EBG provides a -40 dB noise suppression bandwidth of 13.567 GHz. With a substantial increment in the overall area, the nine unit-cell IE-EBG provides a -50 dB bandwidth of 19.02 GHz. The equivalent circuit modeling was developed for nine unit-cell IE-EBG and results are verified with the 3D EM simulation results. In addition, dispersion analysis was performed on the IE-EBG unit-cell to validate the lowest cut-off frequency and bandgap range. The prototype model of the proposed IE-EBG is fabricated and tested. The measured and simulated results are compared; a negligible variation is observed between them. In a multilayer PCB, the solid power plane is replaced with the 1 x 4 IE-EBG power plane and its impact on high-speed data transmission is analyzed with single-ended/differential signaling. The embedded IE-EBG with differential signaling provides optimum MEO and MEW values of 0.928 V, 0.293 ns for a random binary sequence with the 0.1 ns rise-time. Compared to single-ended signaling, embedded IE-EBG with differential signaling maintain good signal integrity and supports high-speed data transmission. [ABSTRACT FROM AUTHOR]

This research paper introduces a ultra-wideband (UWB) multiple input multiple output (MIMO)/diversity antenna with three rejected bands using one compact electromagnetic band gap (EBG) structure. The suggested EBG structure rejects three bands at WiMAX, WLAN, and the X-band within the passband of the UWB antenna. To achieve compactness in the conventional EBG structure, two via and square slots are introduced. This structure contributes to better impedance matching by using tapered feedline and slots in the radiating patch. To improve the isolation among all four compact UWB monopoles, decoupling strips are extended from the ground plane. Furthermore, the |S21| is below 17 dB in between the antenna elements and the envelope correlation coefficient is below 0.5, which are tolerable values within the UWB range. Furthermore, different MIMO/diversity characteristics are also discussed. An FR-4 substrate with dimensions of 38 × 45 × 1.6 mm3 is used for the fabrication of the suggested structure. [ABSTRACT FROM AUTHOR]

In this paper, we present the experimental results obtained in the microwave frequency range using an electromagnetic band gap (EMBG) resonator covered with carbon nanotubes (CNTs) and dedicated to CH4 gas detection. The multi-walled CNTs layer is decorated with gold nanoislands (with sizes between 2 nm and 20 nm) and deposited over the EMBG resonator. The microwave measurements of the CNT-based EMBG resonator in air (no gas) and kept for 60 min inside the chamber filled with CH4 demonstrate a shift in the resonance frequency of about 139 MHz and a phase shift of about 9.63°. A very good sensitivity of about 4.58% was obtained from scattering parameters measurements. A new device for CH4 detection was then fabricated and tested. [ABSTRACT FROM AUTHOR]

For efficient and broadband noise suppression in grid-type power distribution networks (PDNs), a novel TSV-based 3-D electromagnetic bandgap (EBG) structure with an accurate and fast circuit model for predesign is proposed for the first time. The proposed structure is suitable for a silicon interposer-based system-in-package (SIP) for small size, high-density RF applications with the development of various portable terminals or other small devices. It is divided into a 3-D capacitor and a 3-D inductor, which are composed of TSVs and redistribution layers (RDLs). Profiting from the high-density integration of TSV devices, the proposed EBG can overcome the shortcomings of the existing structures, such as narrow bandgaps, large areas, and incompatibility with grid-type PDNs. The new structure effectively suppresses the simultaneous switching noise (SSN) in the interposer generated by chips or other modules. The EBG structure produces a noise suppression bandwidth (below −40 dB) of 13.22 GHz, ranging from 6.69 to 19.91 GHz with a fractional bandwidth (FBW) of 166.9%. Moreover, based on the equivalent circuit model, the bandgap of the proposed EBG can be adjusted by changing the structure parameters for diverse noise scenarios. Subsequently, to further reduce the device size, the EBG isolation wall is designed, and high performance is observed. [ABSTRACT FROM AUTHOR]

In this paper, a compact, low‐profile, and simple monopole antenna is presented that is operated at the frequency of 2.4 GHz in industrial scientific medical band. The monopole antenna is based on the simple rectangular microstrip patch with a rotated T‐shaped slot. Furthermore, a 2 × 2 electromagnetic band‐gap (EBG) array is used in this design to act as an isolator between the antenna and the human body, which additionally increases the performance of the proposed antenna. The final design has an overall size of only 0.9λg × 0.9λg × 0.034λg (60 × 60 × 2.3 mm3) where λg is the guided‐wavelength with respect to RO4003 substrate at the resonant frequency of 2.4 GHz. This can make the structure a good candidate for wireless body area network applications. A prototype of the designed EBG‐based antenna is fabricated over a widely available RO4003 substrate. The measurement results show a gain of 6.52 dBi, a front to back ratio of 12.12 dB, and a total efficiency of 79.87% around the resonant frequency. Furthermore, numerical studies are conducted to evaluate the specific absorption rate (SAR) of the proposed design, which shows by introducing the EBG structure, more than 96% reduction in SAR level is obtained. All simulations are carried out by CST microwave studio software. Key Points: In this paper, a compact, low‐profile, and simple monopole antenna is presented that is operated at the frequency of 2.4 GHz in industrial scientific medical bandThe monopole antenna is based on the simple rectangular microstrip patch antenna with a rotated T‐shaped slot. Furthermore, a 2 × 2 electromagnetic band‐gap array is used in this design to act as an isolator between the antenna and human body, which additionally increases the performance of the proposed antennaThe final design has an overall size of 0.9λg × 0.9λg × 0.034λg (60 × 60 × 2.3 mm3), where λg is the guided‐wavelength with respect to RO4003 substrate at the resonant frequency of 2.4 GHz. This can make the structure a good candidate for wireless body area network applications [ABSTRACT FROM AUTHOR]

In this paper, a backfire suppressed aperture coupled circularly polarized (CP) stacked patch antenna for universal ultra-high frequency (UHF) radio frequency identification applications is presented. Cross-polarized backfire radiation patterns were successfully suppressed by a planar high impedance surface (HIS) reflector. The size of the fabricated antenna is 250 × 250 × 26.9 mm3 (0.71λ0 × 0.71λ0 × 0.076λ0) and its peak gain value of 7.1 dBi is measured. The distance between the antenna and the HIS reflector is only 4.8 mm (0.014 λ0). The HIS reflector suppressed cross-pol backfire radiations by about 10 dB. Detailed antenna and HIS reflector design are discussed thoroughly in this paper. The presented backfire suppression technique using the HIS reflector is scalable to other applications and frequency bands. This paper demonstrates the feasibility of the HIS structure at UHF band. [ABSTRACT FROM AUTHOR]

In this paper, we extend the idea of reducing the electromagnetic interactions between transmitting radiators to the case of widely used planar antennas in printed technology based on the concept of mantle cloaking. Here, we show that how lightweight elliptical metasurface cloaks can be engineered to restore the intrinsic properties of printed antennas with strip inclusions. In order to present the novel approach, we consider two microstrip-fed monopole antennas resonating at slightly different frequencies cloaked by confocal elliptical metasurfaces formed by arrays of sub-wavelength periodic elements, partially embedded in the substrate. The presence of the metasurfaces leads to the drastic suppression of mutual near-field and far-field couplings between the antennas, and thus, their radiation patterns are restored as if they were isolated. Moreover, it is worth noting that this approach is not limited to printed radiators and can be applied to other planar structures as well. [ABSTRACT FROM AUTHOR]

In this research article, a compact wideband stack patch antenna array integrated with compact stack electromagnetic band gap (EBG) structure for multiple input multiple output (MIMO) application is proposed. The wide resonance bandwidth is achieved at 2.45 GHz band by stack arrangement of compact meander line slot driven and parasitic patch elements. The isolation bandwidth is matched with resonance bandwidth with the design of a compact stack L slot EBG structure. The polarization diversity and three-layer EBG structure ensure an enhancement in isolation level. To validate the performance of the proposed stack antenna array, a prototype was fabricated and tested for different MIMO parameters. The measured result confirms the effectiveness of the proposed antenna array in a diverse MIMO environment. [ABSTRACT FROM AUTHOR]

This article proposes the design of two prototypes of magnetic metamaterial lens using rings resonator. The chosen structure is based on CLR resonator (capacitively loaded rings). The designs are conceived as wave guides, in order to reduce the effect of the electric field that causes the increase Signal-Noise Ratio in the coil for animals (Volume Resonator IDR5OD119 from Rapid Biomedical GmbH). This coil is used to obtain images of rats in non-clinical trials. The Siemens Magneton Allegra 3T Magnetic Resonance Imaging equipment was used from the Cuban Neuroscience Center at Larmor frequency of 123.3 MHz. [ABSTRACT FROM AUTHOR]

In this paper, a shape and layout co-optimization method for mutual coupling suppression of MIMO array with non-uniform curved-strip electromagnetic bandgap (EBG) structure is proposed. The curved shape of the EBG structure between the microstrip patches is described to achieve the mutual coupling suppression by the spline curve and moving it the same displacement along the y -axis in both directions, where the spline curve is formed by the coordinates of the control points corresponding to the Bessel function. Moreover, the non-uniform layout design of the EBG structure is introduced to further adjust the radiation field and the surface current distribution of the coupled array. Through simultaneously optimizing the curved shape and layout parameters of the strip EBG structure, the expected array radiation and decoupling performances are obtained. The effectiveness of the proposed method is validated by a MIMO array with edge-to-edge distance of only 0.1λ 0 in the 5G WLAN frequency band. The simulation and experiment results indicate that, compared with non-EBG and the initial uniform strip EBG, the proposed EBG structure can provide the advantage of significantly reducing the mutual coupling to −35.20 dB and effectively improving the isolation between the elements, meanwhile ensuring the MIMO array performances. [ABSTRACT FROM AUTHOR]

Ambient vibrations are one of the promising sources of energy harvesting to power up IoT and WSN nodes. Harvesting random vibrations requires the energy harvester to dynamically tune to the dominant vibration over large frequency band. The tuning is achieved with the help of auto/self-tunable, wideband or broadband energy harvesters. The reported cantilever based harvester is a wideband energy harvester which increases the bandwidth by immersing the moving mass in liquid medium. Splashing of liquid, viscous resistance offered to the moving mass, and the self weight of the liquid contributes to the improved performance over the moving mass based PEH reported earlier. Increased bandwidth is observed for system with two moving cylinders immersed in different liquids. Harvester's proof-mass height is another constraint used to observe the bandwidth change. Effect of viscosity of liquid, liquid filled percentage and amplitude of vibration are reported. The device with increased height of proof-mass and liquid filled for 50% volume shows 63.75% increase in bandwidth compared to the standard device without liquid. [ABSTRACT FROM AUTHOR]

This article presents a compact, cost-effective, and contactless fractal modified electromagnetic bandgap structure (EBG)-based microwave sensing platform for dielectric characterization of liquids by analyzing the variation in the reflection coefficient of an antenna. The reported design is composed of a triangular-shaped antenna (0.323λo × 0.323λo) placed over a 3 × 3 array of Cesaro fractal-based EBG plane (0.67λo × 0.67λo) operating at 2.45 GHz. A significant enhancement of the E-field in the sensing region has been achieved with the incorporation of Cesaro fractals in the EBG plane which results in increased sensitivity and compactness. To validate its performance, absolute solutions of butan-1-ol, methanol, and water are loaded, and a maximum measured sensitivity of 0.875% and a maximum quality factor of 90.05 are achieved. Moreover, a maximum rms error in retrieved values of dielectric constant and loss tangent of liquid under test is found to be 1.092% and 0.813%, respectively. Our demonstrated EBG-based sensor has a compact footprint with good precision, affordability, and ease of operation in detecting liquids for microwave sensing applications. [ABSTRACT FROM AUTHOR]

This study investigates the effect of temperature on the emission frequency of an intrinsic Josephson junction terahertz (THz) electromagnetic wave source, which can be used for high-speed communications by THz carrier wave. The characteristic emission features of two device types (asymmetric and symmetric) and two bias regimes (low and high) were determined. The biasdependent emission frequency was temperature dependent in the asymmetric device, most likely reflecting the temperature-dependent London penetration depth. The bias tunability of the emission frequency can be explained by device self-heating, which significantly and inhomogeneously raises the temperatures of the device from its bath temperature. These findings are consistent with previous studies of temperature distribution in these devices. [ABSTRACT FROM AUTHOR]

We demonstrate the ability to develop one-dimensional electromagnetic band gap structure in X-band waveguide solely by using the positive columns of glow discharges in neon at the middle pressure. Plasma inhomogeneities are distributed uniformly along a typical X-band waveguide with cross section of 23 x 10 mm². It is shown that electron densities larger than 1014 cm-3 are needed in order to create an effective one-dimensional electromagnetic band gap structure. Some applications for using the one-dimensional electromagnetic band gap structure in waveguide as a control of microwave (broadband filter and device for variation of pulse duration) are demonstrated. [ABSTRACT FROM AUTHOR]

We show both theoretically and experimentally reconfigurable properties achieved by plasma inclusions placed in modified surface layers generally used to tailor the transmission and beaming properties of electromagnetic bandgap based waveguiding structures. A proper parametrization of the plasma capillaries allows to reach the neutral inclusion regime, where the inclusions appear to be electromagnetically transparent, letting the surface mode characteristics unaltered. Varying the electron density of the plasma inclusions provoques small perturbations around this peculiar regime, and we observe significant modifications of the transmission/beaming properties. This offers a way to dynamically select the enhanced transmission frequency or to modify the radiation pattern of the structure, depending on whether the modified surface layer is placed at the entrance/exit of the waveguide. [ABSTRACT FROM AUTHOR]

The design of a planar slot array in groove gap waveguide technology implemented by glide-symmetric holes as Electromagnetic Band Gap structure is here presented. Despite the advantages of using holes instead of pins in terms of manufacturing simplicity and cost,the larger size of the holes compared to pins needs to be considered when designing slot arrays without grating lobes. A 1 to 4 corporate feed network is designed using this technology as well. Corrugations are included to further reduce the grating lobes. Experimental results support the viability of the proposed concept for designing glide-symmetric planar arrays of any size. [ABSTRACT FROM AUTHOR]

A method for designing wideband Fabry–Perot resonator antennas (FPRAs) using multilayer partially reflective surface (PRS) is presented. The proposed partially reflecting structure employs a pair of closely spaced PRSs to obtain a positive reflection phase gradient over a wide range of frequencies. Each PRS layer is composed of complementary square apertures and patches printed on either side of a thin dielectric sheet. The distance between the two PRS layers is only λo/12λo being wavelength at the center frequency of 13 GHz). Due to the presence of strong couplings between the two PRS layers, the designed PRS unit cell gives a positive reflection phase gradient from 11 to 15 GHz, thereby forming the basis of a wideband FPRA. Based on the proposed PRS, a compact FPRA with overall dimensions of 2.4λo × 2.4λo × 0.66λo is designed and experimentally validated, which gives a 3 dB gain bandwidth and a maximum realized gain of 32.3% and 14 dBi, respectively. [ABSTRACT FROM AUTHOR]

An effective method combined with finite element method (FEM) and boundary integral method (BIM) is presented in this paper to study the composite electromagnetic scattering from a 2-D coated object partially buried in a 1-D dielectric rough surface. The field within the coated object is modelled by FEM, while the coupling field between the object and rough surface is considered by BIM. The fields inside and outside the object are coupled together via boundary conditions on the boundary of the object. Since the boundary of the object is divided by the rough surface into two parts with different electromagnetic properties, the boundary conditions on the object are more complicated. A detailed derivation of the FEM-BIM formula for the composite model is given in this paper. Our numerical code is validated by the method of moments (MoM), and several numerical simulations are conducted to discuss the scattering characteristics. [ABSTRACT FROM AUTHOR]