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This paper overviews the state-of-the-art of substrate integrated waveguide (SIW) techniques in the design and realization of innovative low-cost, low-profile and low-loss (L3) millimeter-wave antenna elements, feeding networks and arrays for various wireless applications. Novel classes of multilayered antenna structures and sys-tems are proposed and studied to exploit the vertical di-mension of planar structures to overcome certain limita-tions in standard two-dimensional (2-D) topologies. The developed structures are based on two techniques, namely multi-layer stacked structures and E-plane corners. Differ-ent E-plane structures realised with SIW waveguide are presented, thereby demonstrating the potential of the proposed techniques as in multi-polarization antenna feeding. An array of 128 elements shows low SLL and height gain with just 200g of the total weight. Two versions of 2-D scanning multi-beam are presented, which effectively combine frequency scanning with beam forming networks. Adding the benefits of wide band performance to the multilayer structure, two bi-layer structures are investigated. Different stacked antennas and arrays are demonstrated to optimise the targeted antenna performances in the smallest footprint possible. These structures meet the requirement for developing inexpensive compact millimeter-wave antennas and antenna systems. Different structures and architectures are theoretically and experimentally studied and discussed for specific space- and ground-based appli-cations. Practical issues such as high-density integration and high-volume manufacturability are also addressed.

The use of jet thrust for anti-torque for monorotor small helicopters is based on thecirculation control concept, which result in a distributed side force along the entire tail boomassembly. High velocity jets of air from a pressurized tail boom is blown tangential to the surface outof narrow slots that run lengthwise on the side of the tail boom. In combination with the downstreamvelocity produced by the main rotor, Coanda jets cause the flow to remain attached to the tail boomsurface. The anti-torque NOTAR system is in fact the result of Coanda effect and the interest is toanalyze the efficiency of replacing the tail rotor on a small monorotor helicopter.

The esthetic restorations of primary anterior teeth have always occupied an important part of the pediatric dentist′s armamentarium. Various materials have been tried for this purpose and ample materials have been researched in an attempt to fulfill the prerequisites for an ideal esthetic restorative material. Composite resins have been traditionally noted to have decreased bonding ability to primary teeth and the use of secondary retentive features has been advocated to increase bonding. Fifty pairs of anterior class III carious teeth were selected having mirror image lesions on their contralateral proximal surfaces. These teeth were prepared with either a slot or a modified dovetail type of cavity preparation. The patients were then kept on recall to check the clinical characteristics of the restorations at 3, 6, and 12 months. The criteria for evaluation included marginal adaptation, anatomic form, surface discoloration and secondary caries. It was concluded from the results that the both slot and dovetail types of cavity preparations were equally effacious when clinically reviewed for a period of 12 months. Hence the use of slot type of cavity preparation with reduced loss of the tooth structure is indicated for class III cavities in primary anterior teeth.

This paper discusses a miniaturization technique of a compact omnidirectional antenna. A slot loading technique is applied to a well-known low-profile antenna structure whose radiation characteristics are similar to equivalent monopole ones. An equivalent circuit which models the antenna input impedance including the slot effect is also developed in order to illustrate the antenna working principle. The typical dimensions (width x height) of the obtained antenna are λ0/11 x λ0/75 (λ0 is the free space operating wavelength) which makes it a miniature antenna that can be integrated inside small wireless sensor nodes using narrow band communication systems. Its performances are in accordance with classical fundamental limits, the operating bandwidth and efficiency are significantly reduced with the antenna size reduction.

The linear induction motors of hybrid structure have a series of particularities and their most precise estimation of practical flows and outlets has a high level of complexity, especially due to the different form of inductor. The personal contribution on theoretical ground is the justification of the relations for the calculation of practical reactances and outlets, which were also validated by the experimental results using the method of effects' overlapping. The theoretical and experimental results confirm the accuracy of methods and greatly confirm the proposed methods.

This paper presents the design and realization of a simple and low-profile, four-port multiple-input-multiple-output (MIMO) antenna operating in a mm-wave band supporting 5G communication technologies. As part of the design methodology, the initial stage involved the development of a conventional monopole patch antenna optimized for operation at 26 GHz, which was matched to a 50 Ω stepped feed line. Afterward, a square-shaped defected ground structure (DGS) with semi-circle slots on the edges was placed on the ground to improve the isolation, and the circular and rectangular slots were incorporated as DGSs to optimize the antenna impedance bandwidth. Etching semi-circular-shaped slots on the ground plane achieved more than 34.2 dB isolation in the 26 GHz operating band. In addition, an arrangement of four symmetrical radiating elements was positioned orthogonally to minimize the antenna's physical size and improve the isolation. The proposed MIMO antenna's overall dimension was 25 × 25 mm2, which was printed on a Rogers 5880 substrate at a width of 0.787 mm and εr = 2.2. The proposed antenna covered the 5G mm-wave band with a 10 dB bandwidth ranging from 25.28-28.02 GHz, whereas the maximum gain attained for the proposed structure was 8.72 dBi. Additionally, the implementation of these slots effectively mitigated mutual coupling, resulting in reduced envelope correlation coefficient (ECC) values. Furthermore, other MIMO performance metrics, including channel capacity loss (CCL), mean effective gain (MEG), and diversity gain (DG), were analyzed for the proposed structure. The obtained results indicate its suitability for various usage areas, such as smart devices, mobile phones, and sensors in 5G applications.

Copyright of Journal of Gambling Issues is the property of Centre for Addiction & Mental Health and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of compressor aerodynamic parameters, such as pitch-chord ratio, aspect ratio, and fillet, on the cascade performance have been studied in this paper. Slot configuration at the root of the blade has been proved to be an efficient passive control method for the corner separation control in compressor cascade. The combined effects of the pitch-chord ratio, aspect ratio, and blade fillet with a slot configuration on the blade, have also been studied. Larger corner separation caused by the high pitch-chord ratio can be eliminated by the slot, which leads to fewer blades with almost the same or even better cascade performance. Various aspect ratios, together with the slot configuration, have been investigated and all of them have a positive effect on the cascade performance. For the blade with the blade fillet, the slot still has a positive effect on the control of the corner separation, while cascade performance with just a slot configuration is better than the slot configuration under the influence of the blade fillet. [ABSTRACT FROM AUTHOR]

Microring resonator optical buffer is attractive in high-speed optical network system, but ordinary microring resonator use strip waveguide as its basic light guide medium, which cannot provide small footprint, low dispersion and high delay-bandwidth product (DBP) simultaneously. Double-slot waveguide structure was first proposed to construct racetrack-microring resonators. It was found that cascading multiple microrings can increase the delay-bandwidth and lower the dispersion of the resonators by optimizing the structure parameters. Optical buffer cascaded by 8 microrings with flat bandwidth of 20 GHz provided the delay of 150 ps and the dispersion of ~10 ps/nm over 1530-1630 nm, and the footprint of each microring was about 51μm. This study can provide design methods and theoretical basis support for practical application. [ABSTRACT FROM AUTHOR]

ABSTRACT We present a dual resonant substrate integrated waveguide cavity-backed slot antenna with over 34% bandwidth at X-band. A sequential rotation feeding scheme is employed to achieve circular polarization using two differential ports, resulting in excellent isolation. The antenna achieves wideband circularly polarized radiation with symmetric patterns in both principal planes. The full-wave simulation results demonstrate a peak gain of 6.0 dB and a radiation efficiency >96% over the operating impedance bandwidth. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2566-2570, 2016 [ABSTRACT FROM AUTHOR]

ABSTRACT A dual-band substrate integrated waveguide (SIW) antenna with bow-tie shaped slot and two conducting via-holes within the cavity is presented in this paper. The bow-tie shaped slot introduces strong capacitive loading effect, which brings down the TE210 mode of the cavity from 11.08 GHz to 10.3 GHz and the first band of the antenna with 4.94% impedance bandwidth is generated. Another two higher order hybrid modes, generated by incorporating two metallic via-holes, are tuned and merged together by properly optimizing the diameter and position of those two via-holes to obtain the second band of the antenna with comparatively large −10 dB impedance bandwidth of 7.14%. Peak realized gains obtained at both of the frequency bands are more than 5.23 dBi. The simulated and measured results are compared and they are in good agreement. The physical size of the proposed antenna is 22 mm × 32 mm × 0.787 mm. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2303-2308, 2016 [ABSTRACT FROM AUTHOR]

This paper presents an electromagnetic coupling analysis of transient waves excited a rectangular cavity containing an interior scatterer coupled to an external scatterer through a slot. Based on the equivalence principle, time domain integral equations are established by enforcing the boundary conditions on the internal and external scatterers, the slot and the cavity walls. The method of moments is applied in space and time domains to solve the developed system of integral equations. The unknown coefficients of the electric and magnetic currents are approximated by the triangular piecewise functions associated with Dirac function as space basis. To obtain accurate and stable solutions, the Laguerre functions are used as temporal basis. Numerical results involving the coupling effects between the cavity components are investigated. The numerical results are found to be in good agreement with EM theory and literature. [ABSTRACT FROM AUTHOR]

In this paper, a low-profile planar inverted-F antenna (PIFA) for ultrawideband (UWB) applications is proposed. The antenna consists of a PIFA and a ground plane with a slot. The addition of the slot not only improves the impedance matching of the PIFA but also forms an additional resonance. Therefore, the proposed antenna has a wideband characteristic covering the full UWB frequency range (3.1 GHz to 10.6 GHz) and a stable and nearly omnidirectional radiation pattern. The antenna also has a smaller volume and thickness compared to previous UWB PIFAs. [ABSTRACT FROM AUTHOR]

Design, simulation and measurement of high gain annular ringmicrostrip antenna with L-shaped strip for circular polarization is presented. The simulated and experimental results are obtained using Ansoft's commercially available High Frequency Structure Simulator (HFSS, Brookfield WI) software and the Agilen (Santa Clara, CA) vector network analyzer (N5230A.PNA-L), respectively. Parametric study of input characteristics of the proposed antenna is carried out usingmodal expansion cavity model and circuit theory concept. Theoretical, simulated, and measured results show good accord between each other. For the TM12 mode, measured results illustrated an impedance bandwidth and axial ratio bandwidth of 28.20 and 10.4%, respectively. With high gain, low profile, good radiation pattern, and simple structure, it can find potential industrial application in X-band to communicate between peripherals with each other. [ABSTRACT FROM AUTHOR]

Based on the principle and practice of revenue management, this paper studied the slot mutual exchange and allocation problem in liner alliances. A win-win slot mutual exchange and allocation stochastic programming model was established with regard to the factors of multi-routes operated by the liner alliance, as well as the different size and different type of containers. Then, the chance constraint approach was employed to solve the problem. The result of numerical example shows that the established model and its algorithm are feasible and effective. It illustrates that the optimization of slot mutual exchange and allocation could improve the total revenue in liner alliances significantly. Furthermore, it also indicates that the amount of slot mutual exchange and allocation as well as the total revenue are negative to the quantities of contract customer demand and positive to the quantities of demand on spot market. Therefore, it could provide a scientific decision reference on slot mutual exchange and allocation for liners. [ABSTRACT FROM AUTHOR]

In this paper a new directional multilayer coupler based on SIW technology is presented. The suggested MSIW directional coupler works for the operation frequency 5.8 GHz. Ansoft HFSS simulation software is used. The tapered line is used as a transition between MSIW and a microstrip-line for an easy integration. These structures present a good performance such as a good isolation <-34 dB and coupling of -06.37 dB. It presents many advantages of convenient integration, compact size, low cost, massproducibility and easy in fabrication. Simulated results are presented and discussed. [ABSTRACT FROM AUTHOR]

We present a novel Schottky contact photodetector (PD) based on internal photoemission effect (IPE) comprising of a straight air-slot-waveguide (WG) and a metal/silicide stripe buried in a p-type Si microring resonator (MRR) for optical communication. Several metal/silicides are considered for the stripe (PtSi, Pd2Si, TaSi2, and Ag). This PD benefits from the essential features of slot-WGs, MRR-based PDs, and double Schottky barrier (DSB) PDs. For a TaSi2 PD using DSB S-WG-MRR with high Schottky barrier feature, numerical simulation predicts the responsivity of $\sim 0.22$ A/W, a bandwidth-efficiency product of $\sim 10.5$ GHz, and a dark current of 30 pA at room temperature. These characteristics are significantly improved in comparison with those reported for MRR-IPE-PDs. [ABSTRACT FROM PUBLISHER]

ABSTRACT In this letter, a novel technique is proposed to design a dual stopband frequency selective surface (FSS) by combining a bandpass filter with its complementary structure in series. It displays flexibility to control the stopband frequencies which is the most attractive feature of this design. The proposed FSS filter is also very easy to fabricate, consisting of a single metal layer on a dielectric layer. A theoretical equivalent circuit model is proposed to characterize the structure. Explanation of the proposed filter response based on analysis of the equivalent circuit is discussed in detail. It is shown that the frequency response of the proposed FSS is almost the same for different incident angles. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1136-1139, 2016 [ABSTRACT FROM AUTHOR]

The data collision of multiple tags to access the channel is one of the most problems in active Radio Frequency Identification (RFID). The technique of random tag is based on William Feller equation by considering the successful probability (Psuc) may affect to increase the data collision if the tag is not limited the privilege. This paper proposes the modification of William Feller equation by dividing the privilege of tags into several groups. The results show that our scheme can provide the better performances as comparing with William Feller equation in term of successful probability. The maximum average of successful probability is more than 0.97. [ABSTRACT FROM AUTHOR]

A strip/slot hybrid horizontal silicon nitride slot waveguide is designed to provide an ultraflat and low dispersion. By optimizing the height and width of the structure, an ultraflat and low dispersion of ~0 ± 7 ps/nm/km over 812 nm wavelength range (from 1137 to 1949 nm) can be achieved. The waveguide with a 20-nm conformal overlayer has chromatic dispersion within ±1 ps/nm/km over 682-nm bandwidth. So the flatness is 0.0015, which is the lowest flatness in near-infrared regime of this kind of waveguide to our knowl. edge. The influence of the waveguide sidewall to dispersion is also discussed. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In conventional deep-hole pre-splitting blasting to enhance the permeability of low pervious thin coal seam in Southwest China, roof collapse and floor heave usually occurs fracture propagates disorderly in blasting. To maintain the integrity of roof and floor at gate road, a slotting-hydraulic blasting technology was proposed utilizing the fracture guidance of groove blasting and the efficiency of hydraulic blasting. Fracture initiation and stress evolution with coupling charge blasting, slotting air uncoupling charge blasting and slotting-hydraulic blasting techniques were experimentally studied. The results show that the slotting-hydraulic blasting can create two dimensional fractures in large area along expected direction. With the same dose of explosive, exposure area is 1. 42 times and 11 times of that with slot-ting air uncoupling charge blasting and coupling blasting, respectively. Also,the peak stress of explosion is higher than that of slotting air uncoupling charging,up to 1. 5 times. It is also found that larger stress variation occurrs in the apical direction when using slot hydraulic blasting by comparing with the other two methods. This indicates that slot hydraulic blasting can lead to more violent particle vibration which is good for fracture initiation and propagation, and hence can be better for roof and floor integrity. [ABSTRACT FROM AUTHOR]

A new planar omnidirectional antenna with vertical polarization (VP) and horizontal polarization (HP) suitable for base stations is presented and discussed. The proposed antenna is a collinear printed structure, which is designed using the combination of folded microstrip patch array for VP and the modified slot array loaded by metal sheets for HP. This omnidirectional antenna has the advantages of simple structure, low profile, low cost and dual polarizations. An antenna prototype for demonstration is fabricated on a FR4 board with the size of 30 mm (width) × 350 mm (length) × 26 mm (height). The measured 10-dB impedance bandwidths for VP and HP are 445 MHz (2.4–2.845 GHz) and 230 MHz (2.51–2.74 GHz) respectively. The measured gain variation of less than 4 and 2.6 dB in the horizontal plane can be obtained for VP and HP at 2.5 GHz. The measured isolation between the two feeding ports for VP and HP is better than 40 dB over the whole bandwidth. Good agreement between the measured and simulated results can be observed. [ABSTRACT FROM PUBLISHER]

The paper presents a new design methodology for a novel compact rectangular microstrip patch antenna. The initial patch antenna consists of a rectangular-shaped patch using air as substrate, which is primarily used for cost-effectiveness and ease of fabrication. The size reduction procedure started with inserting triangular slots, parallel to the non-radiating edge, properly on the patch. Then gradually slots of different shapes are introduced on the microstrip patch to decrease the resonant frequency and adjusting the patch dimensions so as to alter the surface current path in such a way keeping the resonant frequency constant, and care is also taken to keep the radiation properties unchanged. The antenna parameters depend exclusively on the triangular slot dimensions, their relative positions and orientations relative to each other. The simulated and measured results show that the size reduction is achieved by 78% compared to the conventional rectangular patch antenna operating at the same center frequency. The results obtained provide a workable compact antenna design for incorporation in energy harvesting systems where the aim is to use the rectenna to transfer DC power through wireless links for long distance. [ABSTRACT FROM AUTHOR]

ABSTRACT This work presents the design and fabrication of a wideband dual polarized patch antenna to be used in an array for applications such as satellite communication. Our proposed patch is made of 591 Green Tape made by Low Temperature Co-Fired Ceramic and Rogers RT5870, and is designed to work in the frequency range of 10.7-12.7 GHz. Our result shows that the one layer patch antenna increases the bandwidth up to 17% in simulation and 12.3% in experiment related to the center operation frequency band. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:202-206, 2016 [ABSTRACT FROM AUTHOR]

A computer automated design methodology to synthesize a progressive wave array antenna is presented. The proposed method is based on the generalized-scattering matrix and spherical wave expansion analysis of the array. Mutual coupling effects between radiating elements are inherently considered in the design process. A linearly polarized 24-element irregular slotted array antenna at Ku-band is presented to describe the proposed computer automated design methodology. A prototype has been manufactured to experimentally validate the antenna performance. At the design frequency (17 GHz), 15.9 dB realized gain and 97% efficiency (excluding aluminum losses) values are achieved. Although the array is designed at a single frequency, it shows an overall experimental 7% usable bandwidth. [ABSTRACT FROM PUBLISHER]

An effective feeding procedure for slotted waveguide arrays in the context of so-called groove gap waveguides (GGWs) is presented. Slots are fed through a corporate feed network with E-plane splitters and backed by coaxial cavities, which are more compact than conventional cavities. The coaxial cavity is integrated within the same bed of nails used to host the groove in the gap waveguide. The cavity resonance is generated by merely lowering the height of the desired nail with respect to the surrounding ones. Therefore, no increase in complexity is introduced. The feeding network is built in the same layer as the cavities and the slots, considerably reducing array volume compared to multilayer topologies. A 4 \times 4 slot array has been designed using this concept. The goal of this letter is to demonstrate the viability of groove gap waveguides and coaxial cavities for the design and fabrication of high-frequency single-layer slot-array antennas. Simulation results as well as measurements are shown. [ABSTRACT FROM PUBLISHER]

A 3-D cube antenna with application in wireless sensor network is presented in this letter. Employing microstrip-fed 3-D folded slot antenna topology, a horizontally polarized omnidirectional radiation pattern in azimuth plane was obtained. The structure that is compatible with 3-D printing was fabricated from RO3003 substrate and Objet VeroGray material. The interior of the cubic structure can be used to place electronic circuits of transceiver and sensor. Measurement results verify simulation, and a maximum gain of 1.95 dBi in the azimuth plane and bandwidth of 14% at the center frequency of 2.495 GHz were achieved. The cubic antenna has an edge length of 33 mm and covers the ISM 2.45-GHz frequency band, which has vast application in wireless sensor networks and telecommunication devices. [ABSTRACT FROM PUBLISHER]

The structure of libraries in Altium Designer is described. Approaches to naming of library electronic components – conditionally graphic signs and slots- are offered. Advantages of recommended approaches application are described.

A novel concept of a simple single-pole single-throw switch implementation for a substrate-integrated waveguide is presented in this letter. The switch design is an adaptation from the antenna theory where a resonant slot on a rectangular waveguide, inclined with respect to the line axis, realizes a series impedance load on the waveguide. This impedance can be designed to attenuate the signal flowing through the transmission line while minimizing radiation and can be activated by loading the slot with a diode. A prototype was fabricated to validate the proposed concept. The prototype was measured and it had an ON-state insertion loss of less than 1.3 dB, an OFF-state isolation of more than 10 dB, and a switchable bandwidth of 21% at 22 GHz. [ABSTRACT FROM PUBLISHER]