Wideband performance of 3 dB microstrip‐slot coupler using different substrates
Bibliographic record
Abstract
Abstract This article presents the design of an elliptically shaped microstrip‐slot coupler using different thickness and permittivity substrates that is aimed for operation in 3.0–11.0 GHz band. CST Microwave Studio simulator is applied to its design and performance assessment. Design with the best performance is fabricated to validate the investigation. It is shown that the wideband operation of this type of coupler is predominantly dependent on the substrate's thickness and to a lesser degree on the substrate's permittivity. The degradation in performance is observed for an increased substrate thickness and is explained by the presence of a higher order mode. When the substrate thickness is fixed to a small value and the cutoff frequency of the higher mode is outside the investigated band, there is an optimal permittivity, which offers the best coupler's performance in terms of coupling coefficient, return loss, isolation, and phase difference between the two output ports. In the present investigation, it is found that the best operation is obtained when the substrate's relative permittivity is 4.5 and the substrate thickness of 0.508 mm. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26082
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot 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.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".