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Paneled center-fed reflectarray for bandwidth enhancement

2017· article· en· W2768951313 on OpenAlexaff
Muhammad M. Tahseen, Ahmed A. Kishk

Bibliographic record

Venuenot available
Typearticle
Languageen
FieldEngineering
TopicAdvanced Antenna and Metasurface Technologies
Canadian institutionsConcordia University
Fundersnot available
KeywordsBandwidth (computing)Center frequencyWidebandOpticsPhase centerPhysicsPath lengthPlanarAperture (computer memory)Axial ratioAntenna apertureTelecommunicationsAcousticsRadiation patternEngineeringAntenna (radio)Circular polarizationComputer scienceMicrostripBand-pass filter

Abstract

fetched live from OpenAlex

Regardless of the bandwidth of reflectarray (RA) elements, the RA bandwidth is narrower for many possible reasons. For a RA with small f/D, the ray path length varies as we move away from the center, which is compensated by the elements that are designed at the center frequency. However, as the frequency changes, the path length phase errors grows, as we move away from the center, at a more rapid rate than the element frequency phase variation. Therefore, the phase errors introduced as the frequency changes are so significant deteriorating the aperture phase distribution that causes very low aperture efficiency and in return limiting the gain bandwidth. In order to reduce the path length as we move away from the center, the RA is divided into annular planar panels centered with a small square sub-RA. The annular panels are displaced towards the feed position reducing the path length within each panel. A circularly polarized refectarray designed at 30 GHz with wideband cross Bowtie elements is used as an example. The RA size is 25.25λ × 25.25λ, which is corresponding to 101 × 101 elements. The performance of the antenna is compared with the original RA of the same diameter. The proposed method exhibits the maximum simulated aperture efficiency of 48 %, a 1-dB gain bandwidth of 16.9 %, and the 0.5-dB axial ratio bandwidth of 25.6 %.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.003
Threshold uncertainty score0.009

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0030.002

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.034
GPT teacher head0.293
Teacher spread0.259 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designSimulation or modeling
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations3
Published2017
Admission routes1
Has abstractyes

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