Height-constrained cylindrical helical antennas for satellite-based M2M communications
Bibliographic record
Abstract
Both practical considerations and government regulations are beginning to limit the height of terminal antennas used in satellite-based M2M applications to less than 2.5 cm. For Orbcomm-based systems that operate at downlink and uplink frequencies of 138 and 150 MHz (or a wavelength of 2 m), respectively, 2.5 cm corresponds to a terminal antenna height of just over one-hundredth of a wavelength. Realizing antennas that meet the operating frequency, efficiency and bandwidth requirements of such systems is very difficult, particularly in light of: 1) the manner in which close proximity to a large ground plane reduces the radiation resistance of the antenna and 2) the Chu-Harrington limit on the operating bandwidth of the antenna. In particular, the bandwidth of such heightconstrained antennas barely covers the uplink or downlink passbands of the Orbcomm system so separate transmit and receive antennas are required.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".