Effect of primary feed polarization on phase centre location of parabolic reflector antennas
Bibliographic record
Abstract
Knowledge of the phase centre location of the antenna is of great importance in various applications, such as global positioning system (GPS), remote sensing, radars, and virtual arrays. In parabolic reflectors, the phase centre is located at the center of the aperture plane when it is illuminated by a prime-focus point source feed having an axially symmetric pattern. It is clear that if one displaces the antenna phase centre, the apparent location of the antenna will move resulting in a virtual antenna. The virtual array antenna can be thought of as an antenna having multiple identical beams, with multiple displaced phase centre locations. Such a property is desirable in remote sensing applications, to allow multiple antenna representations. Multiple phase centre reflector antennas were studied in using a dual-mode feed horn as a primary feed. In this paper, the impact of the feed polarization on the phase centre location of offset reflector antennas will be addressed. The feed is a dual mode circular waveguide antenna operating at its fundamental mode, TEn, and the higher order mode TE21. It will be shown that the phase centre displacement can be controlled by simply changing the excitation amplitude and phase of each mode, as well as employing different mode orientations. In particular, the direction of the phase centre movement will depend on the polarization of each mode.
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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 | 0.004 |
| 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) | 0.002 | 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".