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The purpose of this paper is to bring up the concept of multi‐material electromagnetic band‐gap structure (EBGs) and develop a method for its fabrication. Meanwhile, its microwave properties were studied and compared with the traditional EBGs consisting of two kinds of material.

Stereolithography (SL) and gel casting were used to fabricate 3D multi‐material EBGs. Resin mold was designed and fabricated based on SL process, slurries loaded with 55vol per cent Al₂O₃ and 55vol per cent TiO₂, respectively, were prepared, and using gel casting, multilayer EBGs with diamond structure were fabricated. T/R method was used to obtain the characteristic parameter S₂₁ of the EBGs; meanwhile, characters of their band structure were studied based on plane wave expansion method.

The fabricated EBGs with a TiO₂‐resin‐air structure showed a band gap from 11.7 GHz to 16.0 GHz along <1, 1, 0> direction; the EBGs with a TiO₂‐resin‐Al₂O₃ structure showed a band gap from 11.4 GHz to 11.9 GHz along <1, 1, 0> direction. Both of them agreed well with the simulation result. Also, through the study of multi‐material EBGs' microwave properties, it could be seen that this structure was a good approach to adjust the band gap.

With the concept of multi‐material EBG structure brought up, multilayer 3D EBGs were designed and fabricated based on SL combined with gel casting. It could be seen that multi‐material EBGs was a good approach to adjust the band gap. Also, the fact that the testing result matched the simulation validates the feasibility of the process.

The purpose of this paper is to present a new dual-band printed monopole antenna with a partial ground with two notched bands based on electromagnetic band gap (EBG) structures. A new type of EBG antenna with radiation patterns and antenna gains over the operating bands has been developed.

The proposed antenna consists of a pair of EBG structures using a transmission line model. The proposed antenna is designed on an FR4 substrate with a thickness of 1 mm and permittivity (e_r) = 4.3.

The measured results show good dual-band operations with −10 dB impedance bandwidths of 9.1 and 36.2 per cent centered at 2.45 and 6.364 GHz, respectively, which covers the wireless local area network (WLAN) operating bands.

A new type of EBG antenna with radiation patterns and antenna gains over the operating bands has been developed.

The purpose of the study is – in Microwave filter design, the performances of passive components are deteriorated by parasitics at gigahertz (GHz) frequency range. A compact and multi-stack electromagnetic band gap (EBG) structure is proposed with improved stop band characteristics at GHz frequency range in this work. This paper proposes a new design for ultra wide band pass filter (resonator BPF) with periodically loaded one-dimensional EBG to achieve the harmonic suppression. This basic EBG structure is developed with combination of a signal strip and ground plane in the slotted section. The resonator BPF is loaded with one EBG, two EBG and three EBGs to improve the stop-band rejection.

The proposed filter is with multi-stack EBG cell for achieving good pass band and stop bands performance. Circuit model is analyzed in Section 2. Section 3 discuses band pass filter loaded with one EBG. In Sections 4 and 5, filter with two and three EBG loaded resonators are discussed, respectively. Section 6 is concluded with comparison of simulation and measured results.

The stop-band rejection is 20 dB, 40 dB and 50 dB, respectively, in the frequency range of 6 GHz to 20 GHz. The simulation analysis is carried out with advanced system design software. To validate the simulation results, proposed structure is fabricated, and results are found to be in good agreement.

This paper accounts for designing resonator BPF, which has slow wave pass band and stop band characteristics. Second and third harmonics are suppressed using multi-stack EBG. Various stacks with basic designs are proposed and improved results have been demonstrated which is open for future research.

To perform studies and comparisons on the electromagnetic band‐gap (EBG) structures, which are constructed by using a combination of inductive and capacitive elements printed on guided‐wave transmission lines, and by applying a chirping‐and‐tapering technique.

An in‐house solver based on finite‐difference time‐domain (FDTD) method is adopted for analysis. Conventionally, EBG characteristics are formed by a series of perforations, considered as capacitive elements, on the ground plane(s). To enhance the performance, an additional inductive element is implemented, which is realized by narrowing the strip over the respective perforated regions. For further enhancement, a chirping‐and‐tapering technique is applied on the combined EBG structures for comparisons.

Through scattering parameter analysis, it was found that the EBG structures using combined inductive and capacitive elements exhibit a band‐gap behavior superior to the ones built with only inductive or capacitive elements. In another set of comparisons, the modified EBG structures combined with a chirping‐and‐tapering technique resulted in further widening of band‐gap, as well as lower side‐lobes and a smoother transition towards the band‐gap region.

Research was mainly limited to studying solely the EBG structures printed on guided‐wave transmission lines.

The proposed EBG structures may be applied into various areas, such as microelectronics and mobile communications for harmonic suppressions, and into other practical electronic circuit structures.

The ideas on applying combined inductive and capacitive elements on various guided‐wave transmission lines to induce EBG characteristics, together with applications of a chirping‐and‐tapering technique on the combined EBG structures give rise to the research originality.

Application of electromagnetic band gap (EBG) i.e. electromagnetic band gap technique and its use in the design of microstrip antenna and MIC i.e. microwave integrated circuits is becoming more attractive. This paper aims to propose a new type of EBG fractal square patch microstrip multi band fractal antenna structures that are designed and developed. Their performance parameters with and without EBG structures are investigated and minutely compared with respect to the resonance frequency, return loss, a gain of the antenna and voltage standing wave ratio.

The fractal antenna geometries are designed from the fundamental square patch and then EBG structures are introduced. The antenna geometry is optimized using IE3D simulation tool and fabricated on low cost glass epoxy FR4, with 1.6 mm height and dielectric materials constant of 4.4. The prototype is examined by means of the vector network analyzer and antenna patterns are tested on the anechoic chamber.

Combining the square fractal patch antenna with an application of EBG techniques, the gain of microstrip antenna has been risen up and attained good return loss as compared to the antennas without EBG structures. The designs exhibit multi-frequency band characteristics extending in between 1.70 and 7.40 GHz. Also, a decrease in antenna size of 34.84 and 59.02 per cent for the first and second iteration, respectively, is achieved for the antenna second and third without EBG. The experimental results agree with that of simulated values. The presented microstrip antenna finds uses in industrial, scientific and medical (ISM) band, Wi-Fi and C band. This antenna can also be used for satellite and radio detection and range devices for communication purposes.

A new type of EBG fractal square patch microstrip antenna structures are designed, developed and compared with and without EBG. Because of the application of EBG techniques, the gain of microstrip antenna has been risen up and attained good return loss as compared to the antennas without EBG structures. The designs exhibit multi-frequency band characteristics extending in between 1.70 and 7.40 GHz, which are useful for Wi-Fi, ISM and C band wireless communication.

This paper aims to present an efficient method to improve quality factor of printed fractal inductors based on electromagnetic band-gap (EBG) surface.

Hilbert fractal inductor is designed and simulated using high-frequency structural simulator. To improve the quality factor, an EBG surface underneath the inductor is incorporated without any degradation in inductance value.

The proposed inductor and Q factor are measured based on well-known three-dimensional simulator, and the results are compared experimentally.

The proposed method was able to significantly decrease the noise with increase in the speed of radio frequency and sensor-integrated circuit design.

Fractal inductor is designed and simulated with and without EBG surfaces. The measurement of printed circuit board prototypes demonstrates that the inclusion of split-ring array as EBG surface increases the quality factor by 90 per cent over standard fractal inductor of the same dimensions with a small degradation in inductance value and is capable of operating up to 2.4 GHz frequency range.

The purpose of this paper is to investigate of the ultra‐wide band (UWB) characteristics of a conical antenna covered by an electromagnetic band‐gap (EBG) structure composed of alternating high‐ and low‐permittivity dielectric spherical shells.

A finite difference time domain in spherical coordinates is implemented in order to characterize the antenna's performance and waveform fidelity in case an UWB pulse is used. The method of projected effective permittivity is used in order to treat accurately the dielectric interfaces between the dissimilar spherical shells.

The design achieves a very wide impedance bandwidth above 5.5 GHz and presents UWB radiation characteristics and high average gain over the whole bandwidth. The radiation patterns are monopole‐like and their frequency dependence is small in the whole UWB frequency band. A time domain study has shown that the antenna distorts the excitation pulse in a moderate way.

In this paper, a quasi‐planar wideband conical antenna coated on a dielectric EBG structure is proposed for what is believed to be the first time. It is mechanically stable and, relatively easy to build and integrate with the planar circuits.

The purpose of this paper is to present a novel and effective fabricating method of 3D ceramic photonic crystals with diamond structure.

The reverse diamond‐structure resin molds are fabricated by stereolithography (SL), then ceramic slurry is prepared and injected into the molds under vacuum condition. Subsequently, ceramic photonic crystals are obtained after vacuum freeze‐drying and sintering.

The combination of SL, gel‐casting and freeze‐drying could be used to fabricate the 3D ceramic photonic crystals with diamond structure which have intact structure and minimal shrinkage. The samples have been tested and the experimental results indicate that their band gap is in the range of 10.14‐12.20 GHz, consistent with the simulation results.

The influence of fabrication process on the photonic band gap needs further study.

This paper presents a novel fabricating method of 3D diamond‐structure ceramic photonic crystals based on SL, gel‐casting and freeze‐drying. The method fabricates complex ceramic photonic crystals with high accuracy and helps further research in this field.

The purpose of this paper is to investigate the role of electromagnetic band‐gap (EBG) materials in the enhancement of antennas' directivity.

An analysis of a woodpile EBG material is performed, which points out its band properties. Woodpile cavities are then considered, obtained by interrupting the periodicity of the crystal. A woodpile cavity is then superimposed to a double‐slot antenna, resulting in a compound radiating device. The behavior of the EBG and of the radiating structure are simulated through Ansoft HFSS V11.

The woodpile EBG, when used as a cavity, acts as a spatial filter for the radiation coming from the antenna. The directivity of the new radiator is considerably increased, since now the illumination covers an area larger than the antenna.

Using new materials to obtain high‐directivity and compact radiators.

The purpose of this study is to design a radio altimeter antenna whose production process is facilitated and can work with multiple-input multiple-output (MIMO) properties to provide space gain on the aircraft.

To create an easy-to-produce MIMO, a two-storied structure consisting of a reflector and a top antenna was designed. The dimensions of the reflector were prevented to get smaller to supply easy production. The unit cell nearly with the same dimensions of a lower frequency was protected through the original cell design. The co-planar structure with the use of a via connection was modified and a structure was achieved with no need to via for easy production, too. Finally, the antennas were placed side by side and the distance between them was optimized to achieve a MIMO operation.

As a result, an easy-to-produce, compact and successful radio altimeter antenna was obtained with high antenna parameters such as 10.14 dBi gain and 10.55 dBi directivity, and the conical pattern along with proper MIMO features, through original reflector surface and top antenna system.

Since radio altimeter antennas require high radiation properties, the microstrip antenna structure is generally used in literature. This paper contributes by presenting the radio altimeter application with antenna-reflective structure participation. The technical solutions were developed during the design, focusing on an easy manufacturing process for both the reflective surface and the upper antenna. Also, the combination of International Telecommunication Union’s recommended features that require high antenna properties was achieved, which is challenging to reach. In addition, by operating the antenna as a successful MIMO, two goals of easy production and space gain on aircraft have been attained at the same time.