Broadband Performance of Novel Closely Spaced Elements in Designing Ka-Band Circularly Polarized Reflectarray Antennas
Bibliographic record
Abstract
Circularly polarized Ka-band reflectarray (RA) antennas are designed and fabricated using novel broadband closely spaced elements. We present the broadband element study for the Ka-band. Three different circularly polarized RA antennas are developed and fabricated from a single dielectric substrate using three distinct elements, which are optimized. All antennas are made of 625 elements that occupy 6.25 × 6.25λ2at 30 GHz. A circularly polarized Ka-band conical horn antenna is used to excite the RA. The measured results exhibit good agreement with the simulations. Each of the proposed antennas provides an overall 30% bandwidth that represents the measured bandwidth of -10-dB reflection coefficients, 1-dB gain variation, and the 3-dB axial ratio. The estimated maximum aperture efficiency is 55% at 30 GHz. Two larger RAs of size 25.25 × 25.25 λ2(10 201 elements) are designed with focalto-diameter (F/D) ratio 0.59 and 2.74, respectively, to show that the path loss is the main reason affecting the gain bandwidth.
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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 | 0.000 |
| 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 | 0.001 | 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".