EBG Structure Research Articles

Ultra-Wideband Circular Microstrip Antenna with Hybrid EBG for reduced SAR

This article presents a basic ultra-wideband circular microstrip antenna (UWB-CMSA) with partial ground resonating from 2.38 GHz to 12 GHz for handheld devices. The designed antenna covers bands for Bluetooth (2.4 GHz), LTE (2.5/2.69 GHz), WLAN (2.4/3.5/5 GHz), and WiMAX (2.5/3.5/5.5) GHz applications. Specific Absorption Rate (SAR) values of certain bands exceed a limit for UWB-CMSA. The uniplanar spiral unit cell is designed and exhibits phase reversal for 2.4 GHz, 3.5 GHz, and 5.5 GHz. EBG unit cells are placed near the feed for surface wave minimization so as to achieve a reduction in SAR. Furthermore, the EBG structure is placed on the ground plane to analyze the impact, also designs are fabricated and results are compared. Mushroom type M-shaped unit cell is designed which offers phase reversal at 2.3 GHz which is placed near feed in a similar fashion to the earlier spiral one to suppress surface waves also the structure is investigated by arranging it on the ground plane. It is evident that SAR is reduced for all the cases being inspected but for certain bands it exceeds the limit of 1.6 W/kg. A combination of two different unit cells to form a hybrid EBG structure is proposed and evaluated by placing it near the feed. SAR is curtailed by 87.05% at 5.5 GHz.

Compact Embedded Dual Band EBG Structure with Low SAR for Wearable Antenna Application

Compact Embedded Dual Band EBG Structure with Low SAR for Wearable Antenna Application

Analysis of Electrically Couple SRR EBG Structure for Sub 6 GHz Wireless Applications

Analysis of Electrically Couple SRR EBG Structure for Sub 6 GHz Wireless Applications

Compact EBG structure for ground bounce noise suppression in high-speed digital systems

<abstract> <p>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.</p> </abstract>

Hyperparameters optimization of neural network using improved particle swarm optimization for modeling of electromagnetic inverse problems

AbstractOptimization of hyperparameters of artificial neural network (ANN) usually involves a trial and error approach which is not only computationally expensive but also fails to predict a near-optimal solution most of the time. To design a better optimized ANN model, evolutionary algorithms are widely utilized to determine hyperparameters. This work proposes hyperparameters optimization of the ANN model using an improved particle swarm optimization (IPSO) algorithm. The different ANN hyperparameters considered are a number of hidden layers, neurons in each hidden layer, activation function, and training function. The proposed technique is validated using inverse modeling of two meander line electromagnetic bandgap unit cells and a slotted ultra-wideband antenna loaded with EBG structures. Three other evolutionary algorithms viz. hybrid PSO, conventional PSO, and genetic algorithm are also adopted for the hyperparameter optimization of the ANN models for comparative analysis. Performances of all the models are evaluated using quantitative assessment parameters viz. mean square error, mean absolute percentage deviation, and coefficient of determination (R2). The comparative investigation establishes the accurate and efficient prediction capability of the ANN models tuned using IPSO compared to other evolutionary algorithms.

A design of a single element switched beam antenna on Mushroom-like EBG structures

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.

Miniaturized self-isolated UWB MIMO planar/cuboidal antenna with dual X-band interference rejection

The work presents two configurations of four-port UWB MIMO antenna designs with dual notched features. Firstly, a planar four-port UWB MIMO antenna (Design-1) of dimension 31.5 × 34 × 0.8 mm3 is designed by placing four F-shaped radiators over the FR4 substrate board orthogonally. Further, to achieve band-notched characteristics at 7.3 GHz and 8.2 GHz, a pair of mushroom EBG structures and a folded U-shaped slot are positioned over the substrate layer coupled to the feedline and above the radiator, respectively. Secondly, a four-port cuboidal MIMO antenna (Design-2), of dimension 20.8 × 20.8 × 19 mm3 is designed to exhibit band-notched characteristics within the same frequency bands (7.3 GHz and 8.2 GHz). The performance parameters for these designs including the envelope correlation coefficient (ECC) and the diversity gain (DG), are also evaluated and compared. ANSYS HFSS V14.0 tool is used for simulating the designs. For validation purposes, the two prototypes are fabricated and characterized. The measured results are found to be very close to their simulated counterparts.

A design of multi-band and low-profile mushroom-type EBG structure with multi-layer configuration

A design of multi-band and low-profile mushroom-type EBG structure with multi-layer configuration

UWB Multilayer Patch Antenna with EBG Structure for IEEE-C, X, Ku and K Band Applications

UWB Multilayer Patch Antenna with EBG Structure for IEEE-C, X, Ku and K Band Applications

Novel dual-band EBG structure to reduce mutual coupling of air gap based MIMO antenna for 5G application

A novel variable band gap center frequency and dual band gap stacked electromagnetic band gap (VBS-EBG) structure for multiple input multiple output (MIMO) antenna system used for the fifth-generation (5G) technology is presented in this paper. Proposed VBS-EBG is mathematically analyzed using transmission line model. Variation in band gap center frequency of VBS-EBG is simulated using eigenmode solution of high frequency structure simulator (HFSS) for different air gap and experimentally validated. It is observed from simulated and experimental results that proposed VBS-EBG gives more than 29.2 % and 39.13 % broader variation in first band gap and second band gap center frequency respectively, compared to reported variable band gap center frequency EBG structures. Application of the proposed EBG structure to reduced the mutual coupling of MIMO antenna system is carried out. 16.16 dB and 6.05 dB reduction in mutual coupling is observed at first and second resonance respectively of MIMO antenna with proposed EBG structure.

Performance of microstrip patch antenna for single and array element with and without EBG

In this paper, a compact single patch antenna and microstrip array antenna with EBG structures at 6 GHzhave been compained. A surface wave effect is often considered undesirable, since it increased the side lobes, and decreased the antenna gain and effeciency. This problem can be solved by utilizing EBG to suppress of such waves. Above the antenna substrate, the mushroom-like EBG were proposed. The side lobes have been improved from −6.8 dB to −16.5 dB, and better directivity was achieved from 5.77 dBi to 10 dBi and the efficiency improved from (80%) to 95% by using EBG with rectangular antenna. Additionally, the array antenna radiation pattern with EBG was improved to −23.5 dB, and the directivity and effeciency have been improved to 14.3 dBi and to 91.5 respctively. These antenna structures have a great eventuality for use in C band application.

A slotted UWB-MIMO antenna with quadruple band-notch characteristics using mushroom EBG structure

Quadruple notch band dual-port ultra-wideband (UWB) MIMO antenna is reported in this article. The proposed MIMO antenna is designed from a single port UWB antenna, which consists of an arrow-head shaped radiator loaded with two open-ended inverted L-shaped slots (Slot #1 and Slot #2) and one U-shaped slot (Slot #3) followed by a pair of mushroom type EBG structures. The inverted L-and U-shaped slots are liable for generating triple notch band behavior at 3.3 GHz, 4.03 GHz, and 5.4 GHz, respectively. Besides this, the antenna produces an extra notch band function at 6.0 GHz using a pair of mushroom type EBG structures. In addition to this, the antenna covers wideband ranging from 3.0 to 10.7 GHz which suitably meets the requirement of ultra-wideband (UWB) applications. The design is modeled over FR4 Epoxy material and having an overall size of 43 × 34.9 × 1.6 mm3. However, a rectangular decoupling strip is introduced below the substrate layer for reducing mutual coupling between them. Therefore the suggested antenna is having efficient notch controlling capabilities and its performance characteristics are evaluated and analyzed in terms of rejecting frequencies, Current concentrations, ECC, Diversity Gain, and radiation patterns.

A Broadband Dual-polarized Antenna with CRR-EBG Structure for 5G Applications

In this paper, a broadband dual-polarized antenna with concentric rectangular ring electromagnetic bandgap (CRR-EBG) structure is proposed for 5G applications. The antenna consists of a pair of ±45° cross dipoles, an EBG array, and two inverted L-shaped improved feeding structures. In particular the ring part of the feeding structures can reduce the coupling between two ports. The leaky wave area of the EBG structure can be used to increase bandwidths. According to the measured results, the bandwidths of port1 and port2 are 32% (3.04-4.21GHz) and 28.3% (3.13-4.16GHz), respectively. The port-to-port isolation can reach up to 23 dB, and the average gain is approximately 5 dBi. The antenna has the advantages of a wide band, good isolation and a stable radiation pattern, which can be better used in 5G communications.

Performance of defected ground structure with miniaturized microstrip patch antenna using RMPA substrate material

Abstract A parallel structural antenna with the acts slot configuration is indicated for process of 5G wireless technology. The direct slot configuration defined within the patch antenna drives the 5G mid band and twin band frequency reaction in the frequency location without the conditions. Next, a 2-D Double Periodic Electronic Band (EBG) shape is carried out below the metal ground aircraft to request an extended impedance bandwidth for RMPA Materials. The slot duration and feature changed into designed for an impedance bandwidth of 12.49% and 4.49% at three pass band frequencies of 532 GHz and, 835 GHz respectively. Simulated with measured gain and reflection coefficient of correct settlement for bending bandwidths. The antenna array length is 33.5 mm × 33.5 mm. The antenna modified structure and the experimental effects were compared with all the other existing systems. The proposed antenna, which makes use of the EBG structure, suggests pics and excessive sensitivity steady with a massive impedance bandwidth, meeting the necessities of the IoT software program supplied with the resource of 5G technology.

Dual-band pattern reconfigurable antenna using electromagnetic band-gap structure

A pattern reconfigurable antenna offers diverse pattern configurations and beam steering to cater the congested signal environment problem while maintaining the performances and operating frequency, as well as increasing the signal and data security. The pattern reconfigurable antenna using EBG structure is presented in this paper for beam-steering configurations. Most of the previous works proposed the PIN diode on the radiating patches, which caused the degradation of its performances. In this work, the structure offers good efficiency as the RF switches are not embedded to the radiating patches. A dual-band slotted pattern reconfigurable antenna using EBG structure is designed and analyzed. The EBG patches are located at the right and left of the radiating edge of the antenna. The EBG is designed so that its surface wave of band gap covers the radiation of the antenna. As a result, the surface waves excited by the patch antenna are prohibited from propagating by the EBG and caused the radiation pattern to be tilted to another side. The operating frequency of the proposed antenna is 2.45 GHz and 5.8 GHz for the dual-band antenna. The proposed antenna is capable of having beam shifting at three different angles (0°, +26°, and −26°).

A Compact Triple Band EBG Using Interdigital Coplanar Waveguide Structure for Antenna Gain Enhancement

A new triple band EBG unit cell with compact size has been designed, fabricated, and tested. The proposed EBG unit cell is based on a square mushroom-like EBG (M-EBG) structure with an interdigital coplanar waveguide (ICPW). With this technique, the size of the proposed ICPW-EBG structure has been reduced from λ/2 to λ/4 compared with the conventional M-EBG unit cell dimension, which is 18 × 18 mm2. The proposed unit cell was designed in order to respond for three frequency bands at 1.8 GHz, 2.45 GHz, and 3.7 GHz. An array of 10 × 10 unit cell was also designed as a reflector with an overall dimension of 181.8 × 181.8 mm2. The dipole antennas were implemented over the designed reflector with a short distance of λ/8 to radiate electromagnetic wave. The simulation results showed that the ICPW-EBG reflector can improve directivity of the dipole antenna to be 9.12 dB at 1.8 GHz, 9.02 dB at 2.45 GHz, and 8.40 dB at 3.7 GHz. The measurement directivities agreed well with simulation results including 8.72 dB at 1.8 GHz, 8.56 dB at 2.4 GHz, and 8.1 dB at 3.7 GHz. This is the first design of triple band EBG unit cell with 50% size reduction compared with the conventional structure at the same frequency. The designed ICPW-EBG reflector with dipole antenna results in the triple band operation, low-profile and high gain suitable for modern wireless communication systems.

Enhancement of Impedance Matching of Rectangular Patch to the Elimination of the Surface Waves

This paper presents to enhance the input impedance matching of the rectangle microstrip patch due to the dwindling of the surface waves. The properties of this antenna have been enhanced by the enhancement of the input impedance matching. This is to achieve with the use of three techniques, which are the defective ground structure, intrude a U-shaped slot on a patch, and 1-D EBG structure. This antenna has designed on both sides of the FR4 epoxy substrate of a thickness of 1.6 mm at 2.4 GHz to the simulation and fabrication. The results of this antenna have been good agreement between both the simulations and fabricate designs. This antenna can applicable to LTE (4G), WiFI, WiMax, UMTS, and 3G/2G mobile communications.

Improved Microstrip Antennas with Novel EBG Structure for WLAN Applications

Improved Microstrip Antennas with Novel EBG Structure for WLAN Applications

A broadband directional circularly polarized spiral antenna on EBG structure

ABSTRACT A new low profile broadband directional spiral antenna design on a planar EBG structure is introduced which is suitable for aircraft structural integration. The proposed antenna has the (greater than 4 dBiC) gain and axial ratio (less than 3-dB) bandwidth of 400–800 MHz (except for a narrow frequency range of 505–530 MHz) within a total thickness of one tenth of the wavelength. Meausured peak gain is 7.5 dBiC while gain at 400 and 500 MHz are 6 and 7.2 dBiC, respectively. Abbreviations: EBG: Electromagnetic Bandgap; HIS: High Impedance Surface; SATCOM: Satellite Communications; UHF: Ultra High Frequency; CP: Circularly Polarized; BW: Bandwidth; AR: Axial Ratio

Removal of scan blindness of phased array antenna using fourth-order Hilbert curved EBG structure

ABSTRACT It has been shown that the Hilbert curved electromagnetic band gap (HC-EBG) structure effectively reduces the surface wave excitation in the substrate. This paper investigates the performance of HC-EBG structure for probe-fed microstrip patch phased array antenna. The results show that not only the mutual coupling between two elements is reduced about 20 dB, but also the blind angle is removed. Based on the proposed method, a probe-fed microstrip patch antenna phased array 9 × 7 elements are designed and simulated that shows the blind angle has been eliminated without increasing the dimensions of the antenna. Simulation results show improvement in the active reflection coefficient of center element and gain of the array.