Mushroom Electromagnetic Band Gap 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.

Notch band characteristics improvement of a printed ultra wideband antenna by embedding frequency Selective Surface

Excellent improvement on band notched characteristics of a circular ultra-wideband (UWB) printed antenna by embedding Frequency Selective Surface (FSS) at proper position in the far field is presented in this article. A square shaped mushroom Electromagnetic Band Gap (EBG) structure is placed beside the feeding line to achieve an elimination band of 3.7–4.2 GHz over the ultra-wideband range of 2.9–14 GHz showing fractional bandwidth of 131 %. The proposed antenna's electrical dimension is 0.29λ×0.367λ×0.015λ. After embedding the properly designed FSS at optimal position along with the antenna the maximum gain of the radiating frequency increases from 7.1 dBi to 8.1 dBi and notch frequency gain reduces to −7.9 dBi from −5 dBi. Radiation efficiency at notch frequency also reduces from 31 % to 17 %. More than 10 dB Front to Back lobe Ratio (FBR) is obtained at 4.5 GHz. With the aid of Advanced Design Software (ADS), an equivalent circuit for the suggested antenna is created and its response is contrasted with measured and simulated outcomes. The proposed antenna is useful in UWB range with band rejection for C band satellite downlink.

Mutual coupling reduction in antenna arrays using the novel mushroom electromagnetic band gap and defected ground structure

AbstractThe multi‐input and multi‐output antennas have been developed to increase the communication capacity in many applications, but they also bring coupling problems between array elements, which will seriously affect their performance. Therefore, it is of great significance to reduce mutual coupling between array elements. In this article, a novel mushroom electromagnetic band gap (EBG) and defected ground structure (DGS) are introduced to reduce mutual coupling between array elements. Simulation results show that the EBG with metal vias placed between the array elements can improve the port isolation by 36 dB, and the introduced DGS can further suppress the coupling and achieve the decoupling effect of 47 dB. The measured results demonstrate the performance of the proposed structure for suppressing mutual coupling.

Investigation of AFGSM Methods for Some Electromagnetic Bandgap Structures: From Analysis to Applied Antenna Design

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 is 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.

Patch antenna with multi-cell EBG for RF energy harvesting applications

AbstractIn 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.

Wearable textile EBG‐inspired bandwidth‐enhanced patch antenna

An electromagnetic bandgap (EBG)-inspired low-profile wideband textile antenna is presented. By partially surrounding a standard textile patch antenna with mushroom EBG cells, a significant enhancement of the 10 dB impedance bandwidth is obtained. In particular, whereas a standard textile patch antenna exhibits a typical 10 dB bandwidth of 6% for a substrate thickness of 0.04, the proposed technique extends the 10 dB impedance bandwidth to 32%. Notably, the relatively large impedance bandwidth is achieved without extracting a heavy cost in terms of fabrication or design complexity. To make the design amenable for textile implementation, as opposed to more conventional designs which use EBG cells as a replacement for a ground plane, the proposed design hinges on the patch antenna being coplanar with a single quasi-ring of coplanar EBG cells. The proposed antenna design is validated through measurements in free space and on-body, where it is demonstrated to be robust to the effects of bending in the two principal planes.

Gain and isolation enhancement of patch antenna using L‐slotted mushroom electromagnetic bandgap

In this paper, the application of the L-slotted mushroom electromagnetic bandgap (LMEBG) structure to patch antenna and antenna array is investigated. A coaxial fed patch antenna and antenna array are designed at 5.8 GHz, center frequency for ISM band (5.725-5.875 GHz). Two layers of LMEBG are placed around the patch to achieve a gain enhancement of 1.9 dB. Measured results show a bandwidth enhancement of 300 MHz with an additional resonant frequency at 5.6 GHz with 4.5 dB of gain. A 5 × 2 array of LMEBG is used to achieve a 2 dB mutual coupling reduction and 2 dB gain enhancement for a two-element H-coupled patch antenna array.

Enhancing MIMO Antenna Isolation Characteristic by Manipulating the Propagation of Surface Wave

Multiple-input multiple-output (MIMO) antennas have been a mainstream technology in fifth generation (5G) communications. However, strong mutual coupling between both adjacent and nonadjacent elements is inevitable, especially among highly integrated devices. In this paper, a slit embedded mushroom electromagnetic bandgap structure (EBG) is primarily proposed to suppress the propagation of surface wave between antenna elements. Subsequently, complementary split-ring resonators (CSRRs) are periodically arranged in two sides of the ground to steer the surface wave. By effectively utilizing the unusual electromagnetic property of EBG and CSRR to manipulate the propagation of surface wave, the mutual coupling between antenna elements has immensely alleviated. Finally, an H-shape defected ground structure (DGS) is introduced to reinforce decoupling effect. In order to validate the feasibility of the design principle, a prototype of the proposed antenna has been fabricated and measured. Measured results demonstrate that the decoupling concept in this paper is reasonable and approximately 12 dB reduction of mutual coupling is realized.

Metamaterial Properties Applied in Wire Antenna Design

In this paper, metamaterials are used, in order to verify their utilities; two different structures have been considered as a ground. The first one is a mushroom EBG (Electromagnetic Band Gap) structure which is composed of several patches with a ground connecting via, where the second one is a 2D metamaterial structure with resonant rings and digital capacitors. CST, which is based on one of the most popular numerical method Finite-Difference Time-Domain (FDTD) is used. Both the structures are investigated by simulation and compared at the frequency of 12 GHz, the metamaterials properties are successfully verified around the resonant frequency. A very low cost wire is transformed into a valuable circuit by enhancing the directivity and the gain in order to rival other antennas, in order to ensure a large use to the dipole. The digital capacitor has essential part in this work. The antenna proposed in this work is in the frequency band Ku.

High-Gain Patch Antenna Based on Cylindrically Projected EBG Planes

One kind of artificial ground consisting of nonperiodic electromagnetic band gap (EBG) structures with adjustable off-center vias is first proposed. According to the projection equivalence, an artificial plane similarly equivalent to a cylindrical metal reflector can be constructed by proper deployment of the vias in the EBG plane, which can strongly focus electromagnetic waves to realize an extremely directive antenna with a high gain. For demonstration, two X -band high-gain differential-fed patch antennas using the proposed EBG planes are accordingly designed. The simulated and measured results indicate high gains of 14.1 and 11.7 dBi are, respectively, achieved for these two antennas, over 1–2 dB improvement than the antennas based on periodic mushroom EBG structures, thus achieving higher aperture efficiencies of 88% and 107.2%; meanwhile, the gain variations are less than 2 dB in the whole frequency band of interest. Compared with a conventional 2 × 2 patch antenna array, the proposed antenna can not only avoid extra feeding network, but also exhibits a higher gain and a higher aperture efficiency within a much wider working band.

High-Isolation Array Antenna Integration for Single-Chip Millimeter-Wave FMCW Radar

By using the second bandgap in mushroom electromagnetic bandgap (EBG) structures, a high isolation can be achieved between transmitting (TX) and receiving (RX) microstrip array antennas integrated with a millimeter-wave single-chip frequency-modulated continuous-wave (FMCW) radar. These EBG structures are much easier to manufacture at millimeter waves as compared to the first bandgap mushroom EBG structures. In addition to improving isolation, the EBG structures are also used to reduce radiation pattern ripples caused by edge diffractions due to surface waves. Experimental validation is performed on antenna level and on the radar system level. For the system-level validation, the antenna arrays have been integrated with a single-chip mm-wave FMCW radar using the bond-wire interconnect technology. Measurement results in the 57–64 GHz band show the TX–RX isolation of 40 dB, which is 15–20 dB better than the isolation between TX and RX arrays without EBG structures. In addition, the radiation pattern ripple caused by edge diffractions is reduced below 3 dB.

Triple band notched mushroom and uniplanar EBG structures based UWB MIMO/Diversity antenna with enhanced wide band isolation

Triple band-rejection MIMO/Diversity UWB antenna characteristics are described in this paper. Proposed antenna discards worldwide interoperability for microwave access WiMAX band from 3.3 to 3.6 GHz, wireless local area network WLAN band from 5 to 6 GHz and X-Band satellite downlink communication band from 7.1 to 7.9 GHz. Mushroom Electromagnetic Band Gap (EBG) structures helps to attain band notches in WiMAX and WLAN bands. Uniplanar plus shaped EBG structure is used for notch in X-band downlink satellite communication band. Decoupling strips and slotted ground plane are employed to develop the isolation among two closely spaced UWB monopoles. The individual monopoles are 90° angularly separated with stepped structure which helps to reduce mutual coupling and also contributes towards impedance matching by increasing current path length. Mutual coupling magnitude of more than 15 dB is found over whole UWB frequency range. The Envelope Correlation Coefficient is less than 0.02 over whole UWB frequency range.The variations in the notched frequency with the variations in mushroom EBG structure parameters are investigated.The antenna has been designed using FR-4 substrate and overall dimensions is (64 × 45 × 1.6) mm3.

Modeling and optimization of EBG structure using response surface methodology for antenna applications

Electromagnetic Bandgap (EBG) structures are widely used with microstrip antennas for improving antenna efficiency due to their ability to suppress surface waves. To have proper control of surface wave band-gap, it is necessary to have efficient models of the dispersion characteristics of EBG in the irreducible Brillouin zone. A new methodology for optimization of a modified mushroom EBG is presented, based on Response Surface Modeling (RSM) along with Design of Experiments (DoE). Four geometrical parameters which control the surface wave band gap namely the patch width (w), gap between the patches (2g), via radius(r) and the slot width(s) are considered as independent factors and DoE is carried out using Finite Element Analysis (FEA) simulation. The lower (F1) and upper (F2) frequencies of the band gap are extracted from the dispersion characteristics. Mathematical models for F1 and F2 are developed using non-linear regression analysis. Analysis of Variance (ANOVA) is used to study the effect of EBG parameters on the stop band frequencies. The optimum EBG parameters for a stop band in 5–8 GHz frequency range are determined and are found to be: patch width, 6.48 mm, gap, 0.49 mm, via radius, 0.25 mm and slot width, 0.48 mm. The statistical model is validated by experimental results.

Bandwidth Study of the Stacked Mushroom EBG Unit Cells

The stacked mushroom-shaped (SMS) electromagnetic bandgap (EBG) unit cell and its design procedure are presented. The cell structure is suggested to reduce the cell size and overcome the problems of manufacturing mushroom-shaped EBG cells over a thick dielectric substrate for low-frequency and wideband applications. A comparison between the SMS cell and the conventional mushroom-shaped cell is introduced based on the achievable frequency bandgap. Moreover, a parametric study is performed to highlight both the electrical and mechanical advantages of the SMS EBG structure. Finally, a prototype of a packaged microstrip line is built to verify the characteristics learned from the numerical analysis.

Design of band-notched antenna with DG-CEBG

ABSTRACTUltra-wideband (UWB) disc monopole antenna with crescent shaped slot for double band-notched features is presented. Planned antenna discards worldwide interoperability for microwave access (WiMAX) band (3.3–3.6 GHz) and wireless local area network (WLAN) band (5–6 GHz). Defected ground compact electromagnetic band gap (DG-CEBG) designs are used to accomplish band notches in WiMAX and WLAN bands. Defected ground planes are utilised to achieve compactness in electromagnetic band gap (EBG) structures. The proposed WiMAX and WLAN DG-CEBG designs show a compactness of around 46% and 50%, respectively, over mushroom EBG structures. Parametric analyses of DG-CEBG design factors are carried out to control the notched frequencies. Stepwise notch transition from upper to lower frequencies is presented with incremental inductance augmentation. The proposed antenna is made-up on low-cost FR-4 substrate of complete extents as (42 × 50 × 1.6) mm3.Fabricated sample antenna shows excellent consistency in simulated and measured outcomes.

Dual Band Notched EBG Structure based UWB MIMO/Diversity Antenna with Reduced Wide Band Electromagnetic Coupling

AbstractA dual band-notched MIMO/Diversity antenna is proposed in this paper. The proposed antenna ensures notches in WiMAX band (3.3–3.6 GHz) besides WLAN band (5–6 GHz). Mushroom Electromagnetic Band Gap (EBG) arrangements are employed for discarding interfering frequencies. The procedure followed to attain notches is antenna shape independent with established formulas. The electromagnetic coupling among two narrowly set apart Ultra-Wide Band (UWB) monopoles is reduced by means of decoupling bands and slotted ground plane. Monopoles are 90° angularly parted with steps on the radiator. This aids to diminish mutual coupling and also adds in the direction of impedance matching by long current route. S

Compact Electromagnetic Bandgap (EBG) Structure with Defected Ground

ABSTRACTIn this paper, a compact defected ground mushroom electromagnetic bandgap (DG-MEBG) structure is presented. Compactness is achieved by employing a DG in the conventional MEBG. DG-MEBG exhibits a low pass transmission response with a cut-off frequency of 4.2 GHz and wide stop band up to 17 GHz as against a cut-off frequency of 10.4 GHz observed in a conventional MEBG. Thus the proposed DG-MEBG is 60% compact in comparison with a conventional MEBG structure. The measured results show a very good agreement with the simulated ones.

Ultra-Thin UHF Broadband Antenna on a Non-Uniform Aperiodic (NUA) MetaSurface

A new concept to design ultrathin directional broadband antennas using a nonuniform aperiodic metasurface is introduced. The study and design of the NUA metasurface show that, by employing a decreasing taper for both the metasurface patch and their interelement spacing, broad impedance and pattern bandwidths can be attained. Experimental results show that, with a total thickness of 0.04 of the free space wavelength (corresponding to the lowest frequency of operation), an octave bandwidth can be attained, which is significantly larger compared with existing designs on uniform mushroom electromagnetic band-gap structures.

Novel Compact Mushroom-Type EBG Structure for Electromagnetic Coupling Reduction of Microstrip Antenna array

AbstractA novel compact electromagnetic bandgap (EBG) structure consisting of two turns complementary spiral resonator (CSR) and conventional mushroom EBG (CM-EBG) structure is introduced to suppress the mutual coupling in antenna arrays for multiple-input and multiple-output (MIMO) applications. Eigenmode calculation is used to investigate the proposed CSR-loaded mushroom-type EBG (MT-EBG), which proved to exhibit bandgap property and a miniaturization of 48.9% is realized compared with the CM-EBG. By inserting the proposed EBG structure between two E-plane coupled microstrip antennas, a mutual coupling reduction of 8.13 dB has been achieved numerically and experimentally. Moreover, the EBG-loaded antenna has better far-field radiation patterns compared with the reference antenna. Thus, this novel EBG structure with advantages of compactness and high decoupling efficiency opens an avenue to new types of antennas with super performances.

Development of Electromagnetic Band Gap Structures in the Perspective of Microstrip Antenna Design

Electromagnetic band gap (EBG) technology has become a significant breakthrough in the radio frequency (RF) and microwave applications due to their unique band gap characteristics at certain frequency ranges. Since 1999, the EBG structures have been investigated for improving performances of numerous RF and microwave devices utilizing the surface wave suppression and the artificial magnetic conductor (AMC) properties of these special type metamaterial. Issues such as compactness, wide bandwidth with low attenuation level, tunability, and suitability with planar circuitry all play an important role in the design of EBG structures. Remarkable efforts have been undertaken for the development of EBG structures to be compatible with a wide range of wireless communication systems. This paper provides a comprehensive review on various EBG structures such as three-, two-, and one-dimensional (3D, 2D, and 1D) EBG, mushroom and uniplanar EBG, and their successive advancement. Considering the related fabrication complexities, implementation of vialess EBG is an attractive topic for microwave engineers. For microstrip antennas, EBG structures are used in diversified ways, which of course found to be effective except in some cases. The EBG structures are also successfully utilized in antenna arrays for reducing the mutual coupling between elements of the array. Current challenges and limitations of the typical microstrip antennas and different EBG structures are discussed in details with some possible suggestions. Hopefully, this survey will guide to increasing efforts towards the development of more compact, wideband, and high-efficient uniplanar EBG structures for performance enhancement of antenna and other microwave devices.