Multi-stack Technique for a Compact and Wideband EBG Structure in High-Speed Multilayer Printed Circuit Boards

In this paper a novel microstrip antenna is proposed using electromagnetic band gap (EBG) structure for mobile and wireless applications. It covers two mobile bands ranging from (2.20–2.29) GHz and (2.29–2.30) GHz. An extremely compact size EBG structure is applied in a square shape. After applying EBG structure to the proposed design, performance characteristics such as percentage bandwidth and return loss enhance by 5.1% and 5% respectively. Also by changing the feed and shorting pole (via) position, the same structure is used for ISM (2.45 ± 0.05) GHz band with resonant frequency 2.45 GHz. The measured and simulated results show very good agreement. The design structure is fabricated using FR4 substrate with dielectric constant 4.4, loss tangent 0.02 and thickness 1.6 mm.

Patch antenna arrays are used extensively due to their low profile structure, light weight and low cost. Patch antenna arrays have been widely used for a variety of wireless applications. However, a major drawback of this type of antenna arrays is mutual coupling and bandwidth. Mutual Coupling losses can be reduced effectively by placing Electromagnetic band gap (EBG) structures, also called photonic band gap (PBG) structures. In this paper, different types of Electromagnetic Band Gap (EBG) structures are proposed to be placed in between the patch antenna arrays to reduce the mutual coupling loss. These EBG structures are designed as small as possible because of system compactness. Hence the design of novel compact hybrid EBG structures are more challenging for wireless applications. In this paper various hybrid EBG structures showed with and without vias are compared with the defined antenna parameters.KeywordsEBG structurespatch antenna arraysmutual coupling lossstructure realizationband passstop bandcompact sizebandwidthvias

This paper proposes a reconfigured horn antenna with reduced side-lobe radiation by using electromagnetic band gap (EBG) structure. A mushroom-like structure with a circular-shaped patch as unit cell is designed to achieve a complete EBG. The EBG structure is lined on the metal wall along the E-plane of the horn antenna. This causes the surface waves on the metal wall to be suppressed, resulting in lower side-lobe emission. A conducting wedge is inserted on the gap between the EBG structure and waveguide feed aperture to achieve impedance matching in the antenna. In addition, the proposed horn antenna is suitable for high power systems due to a purely metallic construction of the EBG structure.

This paper presents a novel two-layer electromagnetic bandgap (EBG) structure. The studies on the characteristics of the cell are carried out numerically and experimentally. A lumped-LC equivalent circuit extracted from the numerical simulation is used to model the bandgap characteristics of the proposed EBG structure. The influences of geometric parameters on the operation frequency and equivalent LC parameters are discussed. A meander line high performance bandstop filter and a notch type duplexer are designed and measured. These EBG structures are shown to have potential applications in microwave and RF systems.

In this paper, we present an equivalent circuit (EC) based technique which combined with the numerical method to optimize the EBG structures with simple square-loop frequency selective surfaces (FSSs), they can take on in-phase reflection characteristic in some broad-band electromagnetic band gap (EBG) structures. By using the multilayered FSSs in this type of EBG structure, the surface waves and current could stopped effectively. The geometry and working of the antenna with this EBG structure are detailed and the design method is proposed.

Band notched circular monopole antennas for ultra-wide band applications are proposed in this paper. The proposed antennas in this paper can reject worldwide interoperability for microwave access WiMAX band (3.3–3.8 GHz) and wireless local area network WLAN band (5–6 GHz). Antennas utilises mushroom-type electromagnetic band gap (EBG) structures and I-slot embedded edge located via (ELV) EBG structures to achieve band-notched designs. The advantages of band notched designs using EBG structures like notch-frequency tuning, dual-notch antenna designs and stable radiation pattern are also verified. Various antenna designs with slot in EBG structures, variations in placement of EBG structures, number of EBG structures and ELV type EBG structures are simulated. About 30% reduction in size of EBG structures is obtained if conventional mushroom type EBG is replaced by proposed I-slot embedded ELV-EBG structure. Fabricated and measured results are in good agreement with simulated ones.

This paper presents a circularly polarized printed circuit board (PCB) patch antenna using mushroom-like electromagnetic band gap (EBG) structure for gain enhancement. Unlike the popular method of using artificial magnetic conductor (AMC) or EBG structure as the ground of the antenna, we place the mushroom-like EBG structure around the patch antenna to avoid increasing the number of PCB layers. The EBG structure works in-phase reflection around 24.25 GHz by optimizing design. Limited by the size of the antenna, only twelve EBG units can be distributed around the corner-cut square circularly polarized patch antenna. Simulation results show that gain of the antenna enhances 0.8 dB and cross polarized gain reduces about 15 dB, moreover, the axial ratio is also improved.

Electromagnetic Bandgap (EBG) structures are increasingly utilized by a variety of microwave and optical devices as filters for unwanted signals. One such application is their incorporation in power distribution network (PDN) of electronic circuits where the EBG structure replaces one of the reference voltage planes thus forming a shielded EBG structure. The EBG induces a wide (on the order of few GHz) omni-directional stopband in the operating frequency range of the PDN which mitigates the so called simultaneous switching noise (SSN) on the power plane. The challenging aspect in designing an EBG for such applications is to achieve a wide stopband centered at low GHz frequencies while maintaining a reasonably small unit cell size and a low profile. Indeed, the dimensions of the unit cell of the EBG structure for low frequency designs can become relatively large with respect to the size of the host dielectric substrate. Therefore, availability of a systematic design approach that can provide a fast and accurate means of performance prediction to enable geometry tweaking and design optimization will be of critical importance in utilizing EBG structures in such applications.

A novel millimeter-wave (MMW) hybrid isolator is presented to reduce the mutual-coupling (MC) between two closely-spaced dielectric resonators (DR) antennas at 60 GHz. The proposed hybrid isolator consists of a combination of a new uni-planar compact electromagnetic band-gap (EBG) structure and an MMW choke absorber. The design of the proposed EBG unit-cell is based on the stepped-impedance resonator (SIR) technique. The results show that the proposed EBG structure provides a wide frequency bandgap in the 60 GHz band with miniaturization factors of 0.79 and 0.66 compared to conventional uni-planar EBG and uni-planar compact (UC-EBG) structures, respectively. The proposed EBG is then placed between two Multiple-Input Multiple-Output (MIMO) DR antennas to reduce the MC level. As a result, an average of 7 dB level reduction is obtained. To further reduce the MC level, a thin MMW choke absorber wall is mounted vertically between the two DR antennas and above the EBG structure. An average of 22 dB MC reduction is achieved over the suggested bandwidth while maintaining good radiation characteristics. The measured isolation of the prototype antenna varies from -29 to -49 dB in the frequency range from 59.3 to 64.8 GHz. In fact, the proposed hybrid isolator outperforms other hybrid isolation techniques reported in the literature.

This paper presents a design of a dielectric resonator antenna (DRA) for millimeter-wave applications. An electromagnetic band gap (EBG) structure is used in the antenna design to enhance the antenna characteristics. The simulated with and without EBG results of the designed antenna is calculated to show the parameters such as impedance bandwidth, reflection coefficient, and gain. The parameters of the proposed antenna have improved after the periodic unit cell structure (EBG) introduction. The obtained reflection coefficients of the proposed antenna with and without EBG structure are −30.5 dB and −20.8 dB, respectively. In the presence of an EBG structure antenna shows a peak gain of 25 dBi, which is higher than the without EBG (8 dBi) structure. The designed antenna resonates at 33 GHz with an impedance bandwidth of 700 MHz. The Ansys HFSS software is used to design and simulate the proposed antenna.

Electromagnetic Bandgap (EBG) structures have been successfully applied for suppressing the Simultaneous Switching Noise (SSN) between the power and ground planes. Aimed at the relative narrow bandwidth and the poor performance in low frequency of the conventional Uniplanar-Compact EBG (UC-EBG) structure, a novel EBG structure formed by adding spiral-shaped metal strips on the conventional UC-EBG is proposed. This new EBG structure significantly enhance the equivalent inductance between the neighboring nuit cells, as well as change the character of the stop-band. Simulation results show that the new EBG structure can achieve a bandwidth reach 4.35GHz.This stop-band is 47.5% wider than the conventional UC-EBG structure, and 17.5% wider than the reference EBG structure in literature. The excellent SSN suppression is achieved between 0.18-4.53GHz in the depth of -40dB.

Electromagnetic interference is a significant problem in high-speed circuits. To minimize its effect and improve the electrical characteristics of circuits such as signal integrity and electromagnetic compatibility, the application of an electromagnetic isolation structure with electromagnetic bandgap (EBG) is considered. In this paper, a novel wideband EBG structure is proposed for EMI reduction in multilayer printed circuit boards (PCB), in which a kind of improved L-bridge is used as additional series inductance, and the equivalent inductance can be increased significantly. Compared to the traditional mushroom-liked EBG structure with the same parameters, the L-bridge structure can broaden the relative bandwidth to nearly 250%, with a significant decline of the center frequency. The effectiveness and accuracy of this structure are verified by both simulations and measurements. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011. © 2011 Wiley Periodicals, Inc.

Electromagnetic band gap (EBG) structures structure has become a major revolution in radio frequency (RF) and microwave applications due to its unique characteristics of in-phase and band gap in certain frequency ranges. This paper provides a comprehensive review of the implementation of EBG in several antenna applications. It shows that EBG has multiple advantages in antenna design, such as suppressing surface waves, reducing mutual coupling, creating band notch, controlling radiation patterns, improving RFID transmission, enhancing gain and bandwidth, and act as isolation between the antenna and body. It is hoped that this review will lead to more efforts to develop more compact, broadband and efficient EBG structures to improve the performance of antennas and other microwave devices.

A linear dipole array based on wideband electromagnetic bandgap (EBG) is designed in this paper. The linear array is organized along the H plane and the simulated results of an infinite array show that it features a bandwidth of 24.1% (from 5.1 to 6.5GHz) while scanning to 70° in the H plane with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{VSWR &lt; 2.5}$</tex> . Then, a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">${1\times 20}$</tex> finite linear dipole array based on the above element configuration is designed. The array has the ability to scan up to 75° with a gain reduction less than 3 dB at 5GHz, and scan up to 80° with a gain reduction less than 3 dB at 5.7GHz, and scan up to 88° with a gain reduction about 4 dB at 6.1GHz.

A novel two-layer electromagnetic bandgap (EMBG) structure is presented in this paper. This structure can be applied to microstrip-line structures to realise a bandstop property. Owing to its selfresonant characteristics, the proposed EMBG structure is compact enough for the applications in RF bands. As an instance, an antenna duplexer design with the proposed structure is given.