Electromagnetic Bandgap Unit Cell Research Articles

High Gain Compact Antenna-in-Package Solution Using Like Mushroom Electromagnetic Band Gap for Industrial, Scientific, and Medical Band

Abstract A single-feed circularly polarized antenna with electromagnetic band gap (EBG) has been developed for the Industrial, Scientific, and Medical (ISM) bands. The proposed antenna features a square patch with eight slits on each side and corner, along with a cross-slot in the middle. To prevent surface wave excitation caused by the patch antenna's thick substrate, new grounded like-mushroom EBG structures will surround the antenna. The frequency band gap characteristics of the EBG unit cells have been optimized at 5.8 GHz. A row of EBGs squares is 4.73 mm (0.063λo) away from the antenna square patch and surrounds it on all four sides. The proposed mushroom-like structure design improves the antenna's directivity by 43.31%, gain by 32.93%, reflection coefficient by 93%, and radiation efficiency by 35.22%. This topology enables a wide variety of wireless communications applications. Computer simulation technologies (CSTs) were used to generate simulation figures for the proposed antenna, operating at 5.8 GHz. Furthermore, the new Like-Mushroom EBG antenna simulation, experimental results, and other reported works confirm that our approach meets the studied objectives regarding polarization purity, radiation efficiency, high directivity, and gain.

Implementation of EBG Structure to Reduce Surface Wave Excitations for IoT Range Applications

This paper presents the design of antenna for Internet of Things (IoT) applications. The performance of conventional antenna is limited by surface waves due to which it produces a low gain. An attempt is made to reduce the surface wave excitations in conventional antennas with the use of integration of Electromagnetic Band Gap (EBG) cells. The proposed work involves the design of Edge via EBG unit cell at 5.2 GHz and it is simulated with High Frequency Structure Simulator (HFSS) software. The simulation results show that the gain is enhanced by 10% and S11 is reduced by 72%, approximately in the rectangular microstrip patch antenna with Edge via EBGs.

A High Performance All-Textile Wearable Antenna for Wristband Application.

A compact, conformal, all-textile wearable antenna is proposed in this paper for the 2.45 GHz ISM (Industrial, Scientific and Medical) band. The integrated design consists of a monopole radiator backed by a 2 × 1 Electromagnetic Band Gap (EBG) array, resulting in a small form factor suitable for wristband applications. An EBG unit cell is optimized to work in the desired operating band, the results of which are further explored to achieve bandwidth maximization via floating EBG ground. A monopole radiator is made to work in association with the EBG layer to produce the resonance in the ISM band with plausible radiation characteristics. The fabricated design is tested for free space performance analysis and subjected to human body loading. The proposed antenna design achieves bandwidth of 2.39 GHz to 2.54 GHz with a compact footprint of 35.4 × 82.4 mm2. The experimental investigations reveal that the reported design adequately retains its performance while operating in close proximity to human beings. The presented Specific Absorption Rate (SAR) analysis reveals 0.297 W/kg calculated at 0.5 W input power, which certifies that the proposed antenna is safe for use in wearable devices.

A new hybrid method for mutual coupling minimization of an antenna array

<span lang="EN-US">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.</span>

Mushroom like EBG to improve the Gain and Broadband of Patch Antenna for Ku-Band Satellite Application

In order to increase the gain of the patch antenna , a Mushroom-like EBG(Electromagnetic Band Gap ) structure is used . EBG structures enhance the patch antenna’s characteristics of directivity, bandwidth and efficiency . Initially, we determined frequency band gap characteristics of mushroom-like EBG unit cell value by using ANSYS software . The periodic arrangement of such mushroom-like EBG structure was not limited by any inter connecting microstrip lines . Different patches of similar configuration were arranged in a pattern to better improvement in an antenna performance . The final design shows an effective increase in Gain . The current distributions on those metal patches are nearly uniform, allowing for substantial gains throughout the working bandwidth. Keywords—EBG , mushroom-like EBG, ANSYS software ,Broadband .

A new planar microwave sensor for fat-measuring of meat based on SRR and periodic EBG structures

In this paper, we present a novel microwave sensor for sensing the fat of the meat with high sensitivity. We developed the sensor based on a bent transmission line (TL) and connected it to a split ring resonator (SRR). The gaps in the SRR make hot spots. The material under test (MUT) is placed on the hot spot to increase sensitivity. The sensor is surrounded by electromagnetic bandgap (EBG) elements in the final structure to enhance the Q-factor and save the electric field inside of the sensor. The full-wave simulation resonated with this sensor at triple frequencies of 3.4, 4.08, and 4.55 GHz. Additionally, the proposed EBG unit cell covers 2.4–5 GHz. So, it can make an electromagnetic shield for all resonances, and the final sensor shows dual-band characteristics at 3.48 and 4.67 GHz. The sensor is used to recognize the fat ratio in various meat samples. After Full-wave analysis, the equivalent circuit is extracted and modeled with the aid of an advanced design system (ADS). Next, the relation between the frequency shift of S 21 nulls and fat percentages is calculated based on a proposed closed-form formula. In the end, comparing full-wave analysis, experimental results, and the equivalent circuit model shows perfect matching. • Introducing the first planar sensor for detecting the percentage value of the fat in themeat. • Unlike bulky waveguide sensors the proposed sensor is compact but shows a high Q-factor. • The compact planar sensor is based on a transmission line (TL) and split ring resonator (SRR). • The frequency shifts are used for recognizing the material under test and experimental results confirmed simulation. • The circuit model is determined for confirming simulation and experimental and also the interpolated formula is investigated for calculating permittivity as a closed form formula.

Planar EBG Loaded UWB Monopole Antenna with Triple Notch Characteristics

A triple band-notched ultra-wideband (UWB) monopole antenna using a planar electromagnetic bandgap (EBG) design is proposed. The EBG unit cell composed by an Archimedean spiral and inter-digital capacitance demonstrates the notch frequencies. The antenna with EBG cells near the feed line occupies only 30 × 36 mm2 with triple band-rejection characteristics. The three notched bands at 4.2 GHz, 5.2 GHz, and 9.1 GHz can be used in C-band satellite downlink, wireless local area network (WLAN), and X-band radio location for naval radar or military required applications. In addition, the proposed design is flexible to tune different notched bands by altering the EBG dimensions. The parametric analysis is studied in details after placing the EBG unit cells near the feed line to show the coupling effect. The input impedance and surface current distribution analysis are also analyzed to understand the effect of EBG at notch frequencies. The proposed design prototype is fabricated and characterized. A fairly considerable agreement is observed between simulated and measured results.

Circularly polarized hybrid mode substrate integrated waveguide antenna for two quadrant scanning beamforming applications for 5G

Electromagnetic band gap (EBG) based two ports multiple-input and multiple-output (MIMO) substrate integrated waveguide (SIW) antenna for two quadrant beamforming applications using metasurfaces is addressed. A novel SIW structure is employed to achieve beamforming. This work comprises two types of vias having different diameters and lengths in order to achieve multibeam in the first and second quadrant with 120° coverage. Two cross slots tilted at ± 45 ° are etched on top of the structure. The width variation of one of the cross slots achieved beam scanning in first quadrant with coverage of 90°. Additionally, four circular slots are etched on the top metallic layer to improve the axial ratio and the gain of the antenna. Apart from that, two diagonally etched slots help to enhance the gain and radiation properties of the antenna. Furthermore, to get the good mutual coupling and isolation between the two ports, EBG unit cells are deployed on the ground. The proposed antenna shows good right hand circularly polarized radiation within the band with the help of metasurfaces (MS) deployed on an extended part of the substrate. MS also improves the return loss bandwidth. In the end, the diversity properties of the MIMO have been studied as well. The proposed antenna shows good performance in all respects for 5G applications.

Circularly polarized hybrid mode substrate integrated waveguide antenna for two quadrant scanning beamforming applications for 5G

Electromagnetic band gap (EBG) based two ports multiple-input and multiple-output (MIMO) substrate integrated waveguide (SIW) antenna for two quadrant beamforming applications using metasurfaces (MS) is addressed. A novel SIW structure is employed to achieve beamforming. This work comprises two types of vias having different diameters and lengths in order to achieve multibeam in the first and second quadrant with 120° coverage. Two cross slots tilted at ± 45 ° are etched on top of the structure. The width variation of one of the cross slots achieved beam scanning in first quadrant with coverage of 90°. Additionally, four circular slots are etched on the top metallic layer to improve the axial ratio and the gain of the antenna. Apart from that, two diagonally etched slots help to enhance the gain and radiation properties of the antenna. Furthermore, to get the good mutual coupling and isolation between the two ports, EBG unit cells are deployed on the ground. The proposed antenna shows good right hand circularly polarized radiation within the band with the help of MS deployed on an extended part of the substrate. MS also improves the return loss bandwidth. In the end, the diversity properties of the MIMO have been studied as well. The proposed antenna shows good performance in all respects for 5G applications.

In-band RCS reduction antennas using an EBG surface

AbstractThe paper has proposed a multilayer, polarization rotation featured, low radar cross-section (RCS) antenna using electromagnetic band-gap (EBG)-based frequency selective surface (FSS) at 8.25 GHz. Cross-shaped EBG unit cells offer zero reflection phase and −25 dB reflection magnitude at 8.25 GHz. The FSS layer consists of eight cross-shaped EBG unit cells sandwiched between two substrates to offer high absorptivity at the desired band. The circular patch antenna resonating at 8.25 GHz is placed on the top substrate having a lower dielectric constant. Four circular-shaped patches are etched at the four corners of the top layer and are coupled with two feed lines which are aligned 90° to each other at the bottom layer and interconnected diagonally to achieve polarization rotation. The proposed antenna offers a gain of 6.72 dB and an in-band RCS of −21.4 dBsm. Incident energy is backscattered into eight directions separated by angle ϕ = 45°. The proposed antenna has the RCS reduction band of 7.7–9.4 GHz. It offers normalized polarization rotation ratio more than 0.8 within the −40° to 40° angular region at the frequency band 8–8.5 GHz. The measured result using the fabricated prototype agrees well with the simulated one.

Loaded UWB Monopole Antenna for Quad Band-Notched Characteristics

The paper presents a loaded planar monopole ultra-wideband (UWB) antenna exhibiting quad-band notched characteristics. Triple U-shaped slots over the metallic radiating conductor and a meander line electromagnetic bandgap (EBG) structure are loaded near the feed line in the proposed design. These three U-shaped slots are responsible for generating triple band notches at 2.80 GHz (2.53–3.15 GHz, Aviation Service Band), 3.37 GHz (3.23–3.68 GHz, WiMAX band), 4.08 GHz (3.92–4.30 GHz, C-band Satellite Downlink), whereas the EBG unit cell placed near the feedline is responsible for creating additional notched band at 5.95 GHz (5.49–6.19 GHz, C-band satellite uplink), respectively. The antenna has very compact size of 0.71λ0 × 0.8λ0 × 0.03λ0 and is modeled on FR4 substrate using ANSYS HFSS tool. The antenna without any extra arrangement covers an impedance bandwidth ranging from 2.9 to 10.5 GHz which suitably meets the requirement of UWB applications. However, the proposed antenna integrated with U-shaped slots and EBG-unit cell, filters out four different notched frequencies within working bands without disturbing the performance of the monopole antenna. Moreover, the designed antenna is compact in size with improved performance and having efficient notch controlling capacities. Also, the measured performance of the fabricated prototype is in very good agreement with the simulated counterparts.

Design of a highly miniaturized novel electromagnetic bandgap (EBG) material for performance improvement in microwave components

In this paper, a new uniplanar compact spiral-shaped asymmetric electromagnetic bandgap structure for a low-profile antenna is proposed. The proposed EBG design is constructed, with four spiral-shaped radiators are combined with centre element, which printed on an FR-4 dielectric material. The miniaturisation of the EBG unitcell has been achieved by increasing the electrical length of the radiating element. The overall dimensions of the proposed EBG structure is very low about only 0.03 λ0 × 0.03 λ0 (λ0 is the free space wavelength at the resonating frequency of 2.4 GHz). Miniaturization of the proposed EBG structure is 86 % obtained when compared to conventional EBG structure for 2.4 GHz. This spiral-shaped EBG design can adequately suppress surface wave and it exhibits effective band-stop response at resonant frequency 2.4 GHz. The proposed EBG structure also provides improved performance especially peak gain, when it is placed beneath the antenna. A significant improvement in peak gain up to 1.7 dB and 15 % bandwidth at resonant frequency 2.4 GHz has been achieved after integration with proposed EBG design.

An end fire printed monopole antenna based on electromagnetic band gap structure

In this paper, a moderate gain monopole antenna is proposed for GSM and Wi-Max applications. The antenna structure is constructed from a traditional printed monopole on Roger substrate of 3006 family. To enhance the antenna performance ultimately, an Electromagnetic Band Gap (EBG) layer is introduced to the antenna structure. A numerical analysis is applied based on a Finite Integral Technique (FIT) of CST Microwave Studio (CSTMWS) formulations to characterize the EBG unit cell in terms of S-parameters, dispersion and reflection diagram, as well as the constitutive electromagnetic properties. The antenna performance is tested numerically with and without the EBG structure in terms of S-parameters and radiation patterns. It is found that the proposed antenna provides an excellent matching, S11< −10 dB, at 1.85 and 3.3 GHz with 2.88 dBi and 5.8 dBi gain, respectively. Nevertheless, the Finite Element Method (FEM) based on Ansoft High Frequency Structure Simulator (HFSS) software package is invoked to compute the antenna performance. The antenna structure is fabricated and tested experimentally. Finally, an excellent agreement is found between the obtained numerical results from both software packages and measurements.

Dual-band antenna modification by using dual bad EBG structure for WLAN/WiMAX applications

In this paper, a U-slot antenna as represent of dual-band antenna is studied. This antenna covers the WLAN/WiMAX application with a moderate gain of 4.5 dBi. The antenna excites two modes of TM10 and TM20 and consequently with excitation of high order modes surface currents of antenna substrate increase. To overcome this drawback a dual-band electromagnetic bandgap (EBG) is offered and results of EBG unit cell is matched with the U-slot antenna operation bandwidth at two bands. Finally, arrange of unite cell array and antenna for two goals is investigated. As results prove, the combining antenna with EBG cells can solve the mutual coupling effect more than 20 dB and improve gain and bandwidth of antenna for about 3.5 dBi and 1% for each frequency band, respectively.

Flexible EBG‐backed PIFA based on conductive textile and PDMS for wearable applications

AbstractA wearable planar inverted‐F antenna (PIFA) fed by the coplanar waveguide (CPW) and backed with an optimized electromagnetic bandgap (EBG) structure is presented. The antenna is made of conductive textile and polydimethylsiloxane (PDMS), which is a conformal and robust solution to wearable applications. The EBG unit cell is miniaturized according to the equivalent circuit model, and the cross‐polarization is suppressed due to its approximate 180° reflection phase in the orthogonal direction. The measured impedance bandwidth ranges from 2.30 to 2.65 GHz, which covers the 2.4 GHz Industrial Scientific Medical (ISM) band. The antenna keeps a high gain and efficiency above 70% under different conditions including being flat, bent, and close to the human body. The maximum SAR value is limited to 0.612 and 0.330 W/kg under 1 and 10 g standard, respectively. Therefore, the antenna is a promising candidate for wearable applications in various domains.

A Novel Design of Radiation Pattern-Reconfigurable Antenna System for Millimeter-Wave 5G Applications

In this article, a novel design of dielectric resonator antenna (DRA) with a reconfigurable radiation pattern capability is presented. Reconfigurability in the azimuth plane is achieved by symmetrically placing six electromagnetic bandgap (EBG) sectors around the DRA. Each sector is composed of 26 circular-shaped mushroom-like EBG unit cell. In order to achieve 360° pattern reconfigurability with a minimum number of diodes, a network of metallic veins printed on a conductor-backed dielectric slab is used to group and connect the vias in each EBG sector. In addition, a switching p-i-n diode is integrated to the circuit to control the beam steering in the entire azimuth plane toward the respective desired sector by turning on and off the diode. Sixty GHz DRA prototype incorporating the EBG switching circuit is fabricated and tested. Results show 360° pattern reconfigurability in the azimuth plane, with a realized gain of 4.2 dBi, and less than −16 dB impedance matching level over the desired bandwidth are achieved.

Ultra‐wideband Low‐Detectable Coding Metasurface

A coding metasurface is designed based on hybrid Array pattern synthesis (APS) and Particle swarm optimization (PSO) method for ultra-wideband low-detectable application. The metasurface is composed of Electromagnetic band-gap (EBG) structures of two Minkowski fractal elements with reflection phase difference of 180° (±37°) over a wide frequency range. Two different types of EBG unit cell printed on a thin grounded dielectric substrate produce reflection phase difference of about 180 degrees over a wide frequency range. Ultra-wideband Radar cross section (RCS) reduction results from the phase cancellation between two local waves produced by these two unit cells. The diffuse scattering of EM waves is caused by the optimization of phase distribution, leading to a low monostatic and bistatic RCS simultaneously. The proposed metasurface can achieve 10 dB monostatic and bistatic RCS reduction in a wide frequency band from 5.8 to 18.0 GHz with a ratio bandwidth (fH/fL) of 3.10:1 under normal incidence for both polarizations. The theoretical analysis, simulation and experiment results are in good agreement and validate the proposed metasurface can achieve ultra-wideband RCS reduction and diffuse scattering.

Performance prediction of electromagnetic band gap structure for microstrip antenna using FDTD-PBC unit cell analysis and Taguchi's multi-objective optimization method

Finite Difference Time Domain-Periodic Boundary Condition (FDTD-PBC) unit cell analysis of Electromagnetic Band Gap (EBG) structure has evolved as a versatile method due to its unique feature of solving Maxwell's equations in time and space domains. Providing a wideband characterization in a single simulation has been a prominent requirement in fields like wave interactions with high-speed electronics and Radar Cross Section (RCS) design. These requirements are otherwise difficult to attempt using full-wave simulation methods like Method of Moments (MoM) and Finite Element Method (FEM). In this work, a novel combination of Taguchi's multi-objective analysis method, along with FDTD-PBC unit cell analysis, is proposed for the optimization and prediction of EBG structure performance. Taguchi's method converges at a significantly faster rate compared to conventional optimization methods such as Particle Swarm Optimization (PSO) and Artificial Neural Networks (ANN). This study identifies important design variables and control factors such as the dimension of a square-shaped EBG unit cell like the width of the patch (w), height of the substrate (h), permittivity of the substrate (εr), gap width between the cells (g) and radius of the via (r). The impact of each of these control factors on the performance of the EBG structure is analyzed. The performance of the EBG structure is predicted using Taguchi's method for those experiments which are not included in orthogonal array (OA). The measured and predicted results are found to be closely matching with a 10% prediction error.

Reduction of Surface Waves in Arrays using Uni-Planar EBG

Electromagnetic band gap (EBG) structures can be treated as sporadic arrangement of dielectrics. These structures will aid in the coupling reduction in arrays. In this paper, for reducing coupling between array antennas, a new arrangement of EBG structures is presented. The antenna resonates at 5.8GHz, used for wireless requirement. Here 5 × 2 EBG structures are used to reduce mutual coupling more than 20 dB. The antenna substrate dimensions are 36 mm × 68 mm × 1.6 mm. Also, the dispersion diagram was used to design EBG unit cell. In this, a uniplanar EBG configuration which is easy to fabricate without the use of vias is designed for antennas. Their use in coupling reduction of planar antennas and low-profile antenna applications is explored through an effective technique, because the information required is the dispersion diagram and reflection phase of the unit cell. Different Uniplanar-EBGs are used for optimizing current distribution on the antennas, decreasing the coupling between elements and harmonic suppression. As a result, the antenna array performance is improved and minimum coupling is less than -20 dB by using this EBG structure.

Multislot type ultra‐wideband electromagnetic bandgap structure for simultaneous switching noise mitigation

AbstractA compact and cost effective multislot type electromagnetic bandgap (EBG) structure for high noise isolation in ultra‐wideband applications is proposed. The proposed multislot type structure is a hybrid EBG structure with multislot in an alternating impedance EBG unit cell to achieve both the excellent noise isolation and the bandwidth improvement of the noise suppression. This type of the hybrid structure shows a high noise suppression ability of above −40 dB in an ultra‐wideband stop frequency range from 3 to 20 GHz. The performance of the proposed multislot type EBG structure is evaluated and verified by comparing the simulated and measured results.