Novel compact planar electromagnetic band‐gap structure using for ultra‐wideband simultaneous switching noise suppression

In this article, by analyzing the equivalent circuit mode for electromagnetic bandgap (EBG), a novel compact planar EBG structure is proposed for overcoming the drawback of narrow bandwidth of conventional EBG structures. The novel design is based on using meander lines to increase the effective inductance of EBG patches. The simulated and measured results demonstrate the simultaneous switching noise (SSN) can be mitigated with an ultra‐wideband from 280 MHz to 20 GHz at the restraining depth of ?40 dB. Compared with the traditional L‐bridge and meander lines EBG structures, this novel structure has the advantages of suppression bandwidth and fabrication cost. Moreover, signal integrity is achieved by the time‐domain simulation. The proposed structure provides a new kind of theoretical designing reference for EBG structure to improve the bandwidth of restraining SSN. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:429–436, 2014.     

EBG structure with T‐shaped slits for suppression of simultaneous switching noise

In this article, electromagnetic band gap (EBG) structure with T‐shaped slits is proposed for suppressing simultaneous switching noise. T‐shaped slits, bridges, and the solid ground plane are used to constitute the novel L‐EBG structure. Considering a threshold of ?35 dB, the stopband of the proposed EBG structure is about 7.29 GHz which is 1.68 GHz wider than that of a conventional L‐EBG structure. Measurement results confirm the wide bandwidth of the prototype that is predicted in simulations. In addition, the lower and upper cutoff frequencies are estimated by use of lumped‐component circuit models and parallel‐plate waveguide models, respectively. Moreover, the IR‐drop and dc resistance are examined through simulations. Additionally, common signal integrity issues in a power distribution network such as IR‐drop, DC resistance, and eye diagrams are investigated and compared to a conventional L‐EBG structure. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:419–426, 2015.     

New EBG of CSRR with lumped capacitors applied to oscillator harmonics suppression

In this article, a compact electromagnetic band‐gap (EBG) structure is presented to reject harmonics of a crystal oscillator in the power distribution network. Compared to traditional EBG structures of complementary split ring resonator (CSRR), the proposed CSRR adding lumped capacitors (LC‐CSRR) provides a higher rejection‐performance at the series self‐resonant frequency of the lumped capacitors. A four‐layer printed circuit board is designed and fabricated to measure the S‐parameters of the proposed EBG structure, and a harmonics power testing board is presented to measure rejection performance of the proposed EBG structure. The measured results show that the proposed EBG obtains an attenuation of 60 dB over the whole range of global navigation satellite system band. By inserting the proposed EBG structure of LC‐CSRR, we measure that the harmonics powers can be decreased by 28.8 dB between the input and output of the EBG.     

Multilayer EBG structure for ultra‐wide band SSN mitigation using embedded spiral‐shaped planes

A novel multilayer electromagnetic bandgap (EBG) structure with two spiral‐shaped planes embedded between the power plane and the traditional high‐impedance surface (HIS) is presented. The equivalent capacitance between the power plane and the HIS and the self‐inductance of the patch can be increased significantly, while the self‐inductance of the power plane is decreased. The proposed EBG structure performs excellent ultra‐wide band simultaneous switching noise mitigation and keeps signal integrity in high‐speed digital circuits. The suppression bandgap of the design is from 0.6 to 15 GHz at ?30 dB. Good performance is validated by both simulation and measurement. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.     

Modeling of electromagnetic band gap structures: A review

This article represents a comprehensive review of the research carried out on analytical and numerical methods modeling of electromagnetic band‐gap (EBG) structures used in around last two decades. Because of the unique characteristics of the surface wave reduction as well as perfect magnetic conductor (PMC) like behavior, the EBG structures have created their separate existence in antenna engineering society. These structures are being widely used in designing of several microwave planar circuits including printed antennas, printed microwave filters, etc. The purpose of this article is to present an inclusive review of analytical methods as well as numerical methods in the context of modeling of EBG‐structures. Such a review process is rarely carried out in the open literature to the best of authors' knowledge. The review exercise might be helpful to the researchers working on modeling of EBG‐structures as well as of EBG‐structured printed antennas, microwave planar filters, etc.     

Design of defective electromagnetic band‐gap structures for use in dual‐band patch antennas

Generally, the surface wave of an antenna can be suppressed by integrating the electromagnetic band‐gap (EBG) structures. However, to achieve this effect, the EBG cells must be reasonably designed, otherwise it may lead to performance degradation instead. In this article, a dual‐band pinwheel‐shaped slot EBG structure is proposed. When applied to a patch antenna, defects are introduced into 3 rows of the EBG unit cells. The proposed antenna, incorporating EBGs designed with structural defects, to radiate at 4.9 and 5.4 GHz is simulated and tested. The measured results show that the ?10‐dB bandwidth of the proposed EBG antenna is extended by 41% and 25.4% at low frequency and high frequency, respectively. In addition, the peak gain of the proposed EBG antenna is increased by 2.44 dB at 4.9 GHz and 2.86 dB at 5.4 GHz with >40% efficiency. When compared with the periodic EBG antenna, this antenna is more effective. Thus, these experimental results show that the performance of the EBG antenna can be improved by interrupting the periodicity of the EBGs structures.     

A novel electromagnetic bandgap design applied for suppression of printed circuit board electromagnetic radiation

In this article, a novel electromagnetic bandgap structure is applied to a high‐speed printed circuit board, where the proposed concept is to etch with traditional L‐bridge and extended connecting branches on the power plane. To investigate the electromagnetic characteristics of the proposed structure, its transmission performance is determined including an equivalent circuit to numerically predict the lower cutoff frequency. A near field electromagnetic interference measurement is carried out compared to a reference board to investigate the simultaneous switching noise suppression ability.     

A new FDTD scheme analysis for the characteristics of the magnetic‐anisotropic EBG structure

In this article, the new grid finite‐difference time‐domain (NG‐FDTD) method is applied to calculate the dispersion curves of electromagnetic band‐gap structures, and the dispersion characteristics of three magnetic‐anisotropic medium EBG structure are obtained using the NG‐FDTD method. According to these results, we can conclude that the EBG structure of a magnetic‐anisotropic medium, in which the permeability of nondiagonal elements is real, has a much larger band‐stop than that of isotropic EBG. Other magnetic‐anisotropic EBG structures can also increase the first band‐stop. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005.     

EBG design and analysis for wideband isolation improvement between aircraft blade monopoles

A new lightweight multilayer mushroom EBG is proposed to significantly improve the isolation between collocated aircraft L‐band blade monopole antennas. Isolation improvement between two L‐bands (960‐1220 MHz) blade monopoles of nearly 20 dB is obtained with a three‐layer EBG design without requiring any redesigning or tuning of the antennas. Since the proposed EBG structure only contains very thin dielectric sheets and foam substrates it would be a lightweight structure. Moreover, the EBG being a stand‐alone structure from the antenna it can be designed, built, and placed between the antennas as an add‐on device to significantly improve antenna isolation over a relatively wide bandwidth (25%). An experimental EBG structure was built and tested demonstrating wideband isolation improvement performance.     

Design,analysis, and modeling of miniaturized multi‐band patch arrays using mushroom‐type electromagnetic band gap structures

Novel designs of miniaturized multi‐band 1 × 2 patch antenna array with electromagnetic band gap (EBG) for wideband operation are presented in this article. The proposed patch array is composed of three unequal arms fed by CPW‐to‐slotline transitions to widen the impedance bandwidth with multiple resonances. By adding two conventional mushroom‐type EBG (CMT‐EBG) structures on both sides of 100 Ω slotline transitions, the compact wideband patch array (first design) is obtained. This proposed design with CMT‐EBG includes two bands with the measured ranges (S₁₁ ≤ ?10 dB) of 6.65‐6.95 GHz (C‐band) and 8.57‐11.53 GHz (X‐band). Moreover, the proposed 1 × 2 patch array with the 3 × 3 CMT‐EBG array on the one side of the structure (second design) operates at multi‐bands with the measured ?10 dB impedance bandwidths of 5.80‐5.98 GHz, 6.25‐6.47 GHz, and 8.48‐11.52 GHz. The second design compared to the first design introduces a considerable size reduction with more resonance tuning capability. The performance of the proposed designs is analyzed based on the EBG band gap properties near the slotline transitions. These designs with the EBGs indicate prominent features like resonance tuning capability, acceptable miniaturization, and enhanced impedance bandwidth with low‐fabrication cost. In this study, an equivalent circuit model of the proposed first design with EBG is also offered to describe the properties of multi‐band operation.     

Miniaturized rectangular waveguide filters

Two types of miniaturized rectangular waveguide filters are presented. Miniaturization is achieved using the slow‐wave effect of electromagnetic bandgap (EBG) surfaces and the left‐handed properties of split ring resonators (SRRs). The proposed EBG waveguide bandpass filter performs passband in the frequency range, which corresponds to the waveguide with the lower recommended operating band consequently enabling significant miniaturization of the structure. The SRR‐loaded bandstop filter makes use of the effect imposed by left‐handed medium (LHM), which is created by a combination of SRRs and wireline on the dielectric slab. Both filters are designed, simulated, and tested. Experimental results of the SRR‐loaded bandstop filter are presented to demonstrate feasibility of the proposed structures. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.     

Study on relationships of electromagnetic band structures and left/right handed structures

Two types of dual periodic circuits are introduced. The distributions of passbands and stopbands are generated from their dispersion relationships. Based on the study, Brillouin diagrams of three representative special cases are drawn; S parameters of these three cases are simulated by Aglient ADS; the S parameters of one of the three cases are verified by an experiment. The phase characteristics are compared with those generated from the dispersion relationship. The theoretical analysis and the experimental verification show that both types of the periodic structures can behave as electromagnetic band gap (EBG) structures, right-handed structures (RHS), and left-handed structures (LHS), when they operate at different frequency ranges. Thus, the possibility of a physical structure showing these three different characteristics at different frequency ranges is proven.     

Study on relationships of electromagnetic band gap structures and left/right handed structures

Two types of dual periodic circuits are introduced. The distributions of passbands and stopbands are generated from their dispersion relationships. Based on the study, Brillouin diagrams of three representative special cases are drawn; S parameters of these three cases are simulated by Aglient ADS; the S parameters of one of the three cases are verified by an experiment. The phase characteristics are compared with those generated from the dispersion relationship. The theoretical analysis and the experimental verification show that both types of the periodic structures can behave as electromagnetic band gap (EBG) structures, right-handed structures (RHS), and left-handed structures (LHS), when they operate at different frequency ranges. Thus, the possibility of a physical structure showing these three different characteristics at different frequency ranges is proven.     

Pattern reconfigurable metasurface to improve characteristics of low profile antenna parameters

This article proposes a mushroom‐shaped electromagnetic band gap (EBG) structure for the antenna parameter enhancement of low profile antennas in 5 to 15 GHz regime. Three different type antennas including a dipole antenna, a loop antenna, and a monopole antenna are designed for the corresponding operation band, and a 8 × 8 mushroom type EBG structure is designed to obtain exotic behavior for the enhancement of antenna parameters. Bandwidth, return loss (S₁₁), main lobe gain, directivity, side lobe level, front to back ratio, and angular width of each antenna with EBG structure is examined with details. Besides, the designed EBG structure and antennas are fabricated and experimental results are obtained to support numerical ones. In addition, future study of the proposed EBG structure such as microwave imaging in cavity resonators is specified and discussed.     

Planar electromagnetic bandgap structures

This article presents various novel and conventional planar electromagnetic bandgap (EBG)‐assisted transmission lines. Both microstrip lines and coplanar waveguides (CPWs) are designed with circular, rectangular, annular, plus‐sign and fractal‐patterned EBGs and dumbbell‐shaped defected ground structure (DGS). The dispersion characteristics and the slow‐wave factors of the design are investigated. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006.     

Highly‐isolated unidirectional multi‐slot‐antenna systems for enhanced MIMO performance

In this article, an improved approach is presented for designing Electromagnetic Bandgap (EBG) reflectors for slot antennas by using a waveguide aperture source in simulating reflection phase test. In this manner the nonplanar nature of the near field at the location of the source, that is, antenna, as well as its loading effect on the reflector are incorporated in the design of a mushroom‐type EBG structure operating at 5.3 GHz. This EBG design performs as an efficient reflector in normal wave incidence while suppressing the substrate‐bound modes propagating in the azimuthal directions. The designed EBG reflector is employed in several two‐slot‐antenna structures to establish excellent antenna isolation of at least 25 dB and single antenna gain of 5 dB at 5.3 GHz in each scenario. To further reduce coupling, the antennas are reoriented to benefit from polarization mismatch and radiation pattern nulls, resulting in isolation values of above 40 dB for antennas spaced one wavelength apart. The two‐antenna structures are also characterized for MIMO performance in a reverberation chamber and demonstrate an impressive diversity gain of better than 8 dB in a rich multipath environment. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:289–297, 2014.     

Electromagnetic band‐gap structured printed antennas: A feature‐oriented survey

Wireless communication systems are playing an important role in different sectors of human society. Printed antennas are considered as the critical enabling technologies for these systems. The technology related to the design and development of printed antennas have been continuously improved from the structural view of configuration to antenna features improvement. Electromagnetic bandgap (EBG) structures have played a significant role in improving the features of printed antennas. In this paper, authors have restricted a feature–oriented comprehensive survey on EBG‐structured printed antennas. This type of survey is primarily required for the beginner working on EBG structures/EBG‐structured printed antennas. Such a survey process is rarely carried out in the open literature to the best of authors' knowledge. The proposed survey process is confined only to five different feature classifications; bandwidth improvement, gain improvement, dual‐band/multi‐band characteristics, band‐notch characteristics, and compact and low profile, respectively.     

Isolation enhancement between tightly spaced compact unidirectional patch‐antennas on multilayer EBG surfaces

In this article, ultracompact unidirectional patch antennas are used in different two‐antenna systems for biomedical applications at 5.2 GHz. Multilayer mushroom type electromagnetic bandgap (EBG) structures are designed as slow‐wave medium to reduce the size of the individual patch antennas to 0.1λ₀ by 0.18λ₀. Various techniques are investigated herein to improve antenna isolation for an enhanced Multiple‐Input Multiple‐Output (MIMO) performance. First, the coupling between 0.3λ₀‐spaced antennas is verified to occur dominantly through radiation and near‐field coupling between the patches rather than through substrate‐bound modes. Second, various configurations are proposed to suppress antenna coupling. These approaches include reorientation of the antennas and employment of parasitic radiators between the patches. A novel design is presented in which a unidirectional parasitic slot radiator on an EBG reflector is inserted between the antennas to decouple them. Measurement results confirm efficacy of these approaches in mitigating antenna coupling by more than 11 dB in the operating bandwidth of the antennas. The compact patch antennas maintain efficiency values of higher than 70%. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:30–38, 2015.     

Mutual coupling reduction by SIW ZOR elements on broadside high gain CP beam steering array

In this article, a new circularly polarized (CP) beam steering array antenna based on substrate‐integrated‐waveguide (SIW) is proposed for mm‐wave applications. To generate a wider half power beamwidth (HPBW) and reduce mutual coupling effect a radiation element relying on zeroth order resonance (ZOR) technique has been used which has a treatment such as electromagnetic band gap (EBG) structure to have a specific structure. The antenna element can operate in a bandwidth from 33.82 to 36.37 GHz and AR bandwidth from 34.32 to 35.94 GHz. Besides, the propose element has a HPBW wider than 103°, and a maximum gain of antenna is of 9.2 dBic. A 4 × 4 Butler matrix feed network based on SIW feeding technique is then designed. This feed network includes novel techniques in designing cross‐over and broadband phase shifter. The synthesis of proposed Butler matrix and ZOR elements lead to a four‐beam array antenna with circular polarization can cover a beam switching angles range more than 44° with a gain of 17.6 dBic.     

Reduced mutual coupling of compact MIMO antenna designed for WLAN and WiMAX applications

This communication describes a simple compact wide band multiple input multiple output (MIMO) antenna for Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) applications. The proposed antenna is integrated with an electromagnetic band gap (EBG) structure which is used to reduce the mutual coupling between the ports. The structure is excited by a line feed mechanism and investigated experimentally. The antenna covers the frequency range from 2.01 to 3.92 GHz with the corresponding fractional bandwidth of 64.42%. It fulfills the bandwidth requirements of WLAN (2.35‐2.5 GHz) and WiMAX (3.2‐3.85 GHz) bands where minimum port isolation is obtained around 29 dB throughout the entire application band. The proposed MIMO antenna has very low envelope correlation co‐efficient (ECC < 0.01) and high diversity gain (DG > 9.8). It also has very low channel capacity loss (CCL) which is found to be less than 0.2 Bit/s/Hz. The simulation results are compared with the measurement outcomes and found a good agreement between them.