Frequency bandwidth adjustment of dual-polarized four-arm Archimedean spiral antennas
Bibliographic record
Abstract
In center-fed four-arm Archimedean spiral antennas, broadside radiation patterns with dual-polarized operations in both senses of circular polarization can be realized by confining the spiral circumference to less than three wavelengths. Such antennas with orthogonal circularly polarized waves are excellent candidates for frequency reuse applications, such as multimode Global Positioning Systems (GPS), modern satellite navigation, and radar systems. These dual-polarized antennas improve the wireless channel capacities with higher bit-rate capabilities. A compact, unidirectional, and air-filled structure of the four-arm Archimedean spiral antenna has been proposed by the authors in [1], where both right- and left-handed circularly polarized waves are produced over a respectable frequency band. As it is known, inserting dielectric materials into an antenna structure is widely used to miniaturize the antenna structure, as it leads to an increased electrical path length [2]. Generally, high-contrast substrates are needed in order for a significant reduction in the antenna size. However, the associated dielectric loss becomes particularly troublesome, which deteriorates the antenna efficiency performance. Low contrast dielectric materials, on the other hand, become quite beneficial for frequency tuning of already compact antenna structures, without a significant degradation in antenna performance.
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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 | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".