Characteristics of a broadband printed quadrifilar helical antenna employing a novel compact feeding circuit
Bibliographic record
Abstract
A broadband printed quadrifilar helical antenna employing a novel compact feeding circuit is proposed in this paper. Good results have been obtained in simulation for the quadrifilar antenna alone. To feed this antenna, a circuit based on an aperture-coupled transition and including two 90° surface mount hybrids has been designed. The measured return loss of this circuit is greater than 12 dB between 1.06 and 1.64 GHz, the maximum output magnitude imbalance is 0.5 dB, and the maximum output phase imbalance is 3° over the same bandwidth. Simulations have been carried out to evaluate the effect of the aperture in the ground plane on the antenna performance. The simulated active return loss has been found to be equal to or greater than 10 dB and the gain varies between −0.5 and 3.5 dBc from 1.27 to 1.63 GHz. The HPBW is 144°, and the cross-polarization rejection is greater than 14 dB over the HPBW. At 1.4 GHz, the AR is lower than 3.3 dB over the HPBW. A 16-dB back-radiation level of the LHCP has been noticed in this case at 1.4 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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".