Permittivity measurement of disk and annular dielectric samples using coaxial transmission line fixtures. part I: theory and formulation
Bibliographic record
Abstract
One way of measuring the permittivity of circularly shaped dielectric samples is to measure the S-parameters of a two-port coaxial transmission line fixture into which the samples are placed. Among the sample forms that can be fitted into coaxial waveguides are (1) circular disks and (2) annular rings. The former type is sandwiched between two disjointed inner conductors of the coaxial line, whereas the latter dielectric form is snug-fitted to become the insulation layer of an intermediate coaxial section. Each type of sample requires a different coaxial configuration; this work studies both fixtures. The investigation of the first type is based on a previously studied technique that treats the sandwiched circular disk as a parallel-plate capacitor. Because of inaccuracies in the original form of that method, a modified version that offers improved accuracy is devised here. In addition, a new, independently developed technique for accurately characterizing dielectrics of the second form (annular-ring samples) using quadratic curve fitting is proposed. The experimental fixture, comprising a connected series of coaxial waveguide sections, is numerically treated with the method of moments and mode-matching technique. Details of the theoretical groundwork are presented in this paper, which constitutes the first of two parts of this work. Part II, also appearing in this issue, describes the measurement technique in detail and presents simulation results of the experimental procedure based on the formulation presented herein. In addition, the method that treats circular disks is also investigated in Part II and is used to make comparative performance studies.
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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 | 0.000 | 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 | 0.001 |
| Open science | 0.001 | 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".