Mutual Coupling in Longitudinal Arrays of Compound Slots

Montesinos-Ortego, I.; Sierra‐Pérez, M.; Zhang, Miao; Hirokawa, Jiro; Ando, Makoto

doi:10.2528/pierb12100803

Cited by 5 publications

(6 citation statements)

References 12 publications

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“…Fig. 11 is also qualitatively consistent with the fact that the brightest debris discs are only found around hosts with higher metallicities (see Moro-Martín et al 2015;Montesinos et al 2016). We note again that multi-fragment population synthesis may quantitatively change the results but we expect the positive trend between debris disc mass and [M/H] to remain true.…”

Section: Preliminary Comparison To Observationssupporting

confidence: 84%

“…(v) We also found that our model predicts an increase in the mean mass of the debris disc with metallicity of the host star, as found by Gaspar, Rieke & Ballering (2016). Related to that correlation, if only the brightest (most massive) debris discs are considered, then this result predicts a lack of bright debris discs at low [M/H] environments, as found by Moro-Martín et al (2015); Montesinos et al (2016).…”

Section: Comparison To Observationsmentioning

confidence: 55%

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Planets, debris and their host metallicity correlations

Fletcher¹,

Nayakshin²

2016

Mon. Not. R. Astron. Soc.

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Recent observations of debris discs, believed to be made up of remnant planetesimals, brought a number of surprises. Debris disc presence does not correlate with the host star's metallicity, and may anti-correlate with the presence of gas giant planets. These observations contradict both assumptions and predictions of the highly successful Core Accretion model of planet formation. Here we explore predictions of the alternative Tidal Downsizing (TD) scenario of planet formation. In TD, small planets and planetesimal debris is made only when gas fragments, predecessors of giant planets, are tidally disrupted. We show that these disruptions are rare in discs around high metallicity stars but release more debris per disruption than their low [M/H] analogs. This predicts no simple relation between debris disc presence and host star's [M/H], as observed. A detected gas giant planet implies in TD that its predecessor fragment was not disputed, potentially explaining why DDs are less likely to be found around stars with gas giants. Less massive planets should correlate with DD presence, and sub-Saturn planets (M p ∼ 50 M ⊕ ) should correlate with DD presence stronger than sub-Neptunes (M p 15 M ⊕ ). These predicted planet-DD correlations will be diluted and weakened in observations by planetary systems' long term evolution and multi-fragment effects neglected here. Finally, although presently difficult to observe, DDs around M dwarf stars should be more prevalent than around Solar type stars.

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Section: Preliminary Comparison To Observationssupporting

confidence: 84%

Section: Comparison To Observationsmentioning

confidence: 55%

Planets, debris and their host metallicity correlations

Fletcher¹,

Nayakshin²

2016

Mon. Not. R. Astron. Soc.

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“…In addition, some work showed that the analytical results in the case of considering the mutual coupling in the calculations of the slots excitations are very close to those resulting from CST simulation software 40,47,48 . Taking into account the mutual coupling effects, the radiation characteristics can be slightly enhanced in terms of the SLLs and return loss.…”

Section: Design Proceduresmentioning

confidence: 62%

“…24 In addition, some work showed that the analytical results in the case of considering the mutual coupling in the calculations of the slots excitations are very close to those resulting from CST simulation software. 40,47,48 Taking into account the mutual coupling effects, the radiation characteristics can be slightly enhanced in terms of the SLLs and return loss. In this work, we were able to achieve the desired SLL at the required resonance frequency, and hence any further enhancement that can result from including the mutual coupling effects in the design equations is not essential for the overall results.…”

Section: Mutual Coupling Between the Coupling And Radiating Slotsmentioning

confidence: 99%

Design procedure for planar slotted waveguide antenna arrays with controllable sidelobe level ratio for high power microwave applications

Misilmani

Al‐Husseini

Kabalan

2020

Engineering Reports

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This article presents a complete design procedure for planar slotted waveguide antennas (SWA). For a desired sidelobe level ratio (SLR), the proposed method provides a pencil shape pattern with a narrow half power beamwidth, which makes the proposed system suitable for high power microwave applications. The proposed planar SWA is composed of only two layers, and uses longitudinal coupling slots rather than the conventional inclined coupling slots. For a desired SLR, the slots excitation in the radiating and feeder SWAs are calculated based on a specified distribution. Simplified closed-form equations are then used to determine the slots nonuniform displacements, for both the radiating and feeder SWAs, without the need to use optimization algorithms. Using simplified equations, the slots lengths, widths, and their distribution along the length of the radiating and feeder SWAs can be found. The feeder dimensions and slots positions are deduced from the dimensions and total number of the radiating SWAs. An 8 × 8 planar SWA has been designed and tested to show the validity of the proposed method. The obtained measured and simulated results are in accordance with the design objectives. K E Y W O R D S antenna arrays, high power microwave applications, slotted waveguide antennas, sidelobe level ratio 1 INTRODUCTION High power microwave (HPM) technology is well known in both military and commercial applications. 1 An efficient antenna to be used as the radiating system for these applications is required to have a well directive pattern, large sidelobe level ratio (SLR), and high gain. It should also have high power handling capability required to extract the HPMs from their source. Slotted waveguide antennas (SWA) 2 are taking a major interest in this field, with their major ability of beam pointing and HPM handling capability. 3 SWAs can be also directly connected to Reltron HPM sources, without the need for additional mode converter, which makes them suitable for HPM applications. SWAs are also used in wireless technologies, maritime, and space applications. SWAs are made of rectangular waveguides, having slots cuts used to radiate the energy. 4 The conventional cuts have a rectangular shape. The slots can be made either on the broadwall or the narrow wall of the waveguide, with the most This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

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“…A control of electrodynamic characteristics of the radiators and coupling slots can be realized, first of all, by varying slot geometric dimensions and positions relative to the waveguide walls under conditions that the coordinate system axes associated with the slot and waveguide are parallel. One of the ways to achieve required frequency-energy and spatial characteristics of slot radiators consists in varying an inclination angle of a longitudinal slot axis relative to coordinate waveguide axes [8][9][10][11][12]. In this case, the single slot cut in the waveguide end wall, in contrast to the one located on its side walls, can radiate up to 100% of the supplied power.…”

Section: Introductionmentioning

confidence: 99%

Radiation of Electromagnetic Waves by an Arbitrarily Oriented Slot at the End Wall of a Rectangular Waveguide

Nesterenko¹,

Katrich²,

Kijko³

et al. 2021

PIER C

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A problem of electromagnetic waves radiation diffracted at a narrow rectilinear arbitrarily oriented slot cut in an end wall of a semi-infinite rectangular waveguide is solved by an asymptotic averaging method. The slot radiates into a half-space over an infinite perfectly conducting plane. An influence of slot inclination angle upon energy and spatial characteristics is numerically studied. Theoretical results are compared with experimental data. A numerical-analytical problem of a narrow rectilinear slot radiating into the space above an infinite impedance plane is also presented. The asymptotic solution for the slot magnetic current was obtained by a generalized method of induced magnetomotive forces (MMF) by using Green's functions of a space above the impedance plane. The effect of the plane with impedance coating on the slot is reduced taking into account an additional term to the slot external conductivity, for which the expressions were obtained in an analytical form.

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Mutual Coupling in Longitudinal Arrays of Compound Slots

Cited by 5 publications

References 12 publications

Planets, debris and their host metallicity correlations

Planets, debris and their host metallicity correlations

Design procedure for planar slotted waveguide antenna arrays with controllable sidelobe level ratio for high power microwave applications

Radiation of Electromagnetic Waves by an Arbitrarily Oriented Slot at the End Wall of a Rectangular Waveguide

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