Compact Dual Circularly Polarized Primary Feeds for Symmetric Parabolic Reflector Antennas
Bibliographic record
Abstract
Four-arm Archimedean spiral antennas, capable of generating both senses of circular polarization with broadside radiation patterns, are investigated as a primary feed in symmetrical parabolic reflector antennas with circular rims. Unidirectional, center-fed, and compact spiral antennas are studied, backed by a planar reflector as a ground plane. Both right- and left-handed circularly polarized fields with broadside radiation patterns, according to the first and third modes of the spiral, are realized by confining the radiation zone to less than a three-wavelength circumference. The proposed feed exhibits excellent pattern symmetry and axial ratios well below 0.5 dB at the boresight direction for both senses of polarization. In this letter, the performance of the proposed spiral antenna is fully addressed as primary feeds in symmetrical parabolic reflector antennas. Different antenna parameters such as gain, cross polarization, and efficiency are studied for paraboloids, having different focal-length-to-diameter ratios, for both senses of circular polarization. Efficiencies of 70% and higher are obtained over a frequency band of 2.5-5.0 GHz.
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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 | 0.000 |
| Open science | 0.000 | 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".