Ka-Band Self-Calibration Direct Modulator for Space Applications
Bibliographic record
Abstract
This paper describes a development work of a high-speed Ka-band digital direct modulator performed in COM DEV for on-board application based on a novel self- calibration technique developed by CRC Canada. Direct modulations can significantly simplify up-conversion hardware and improve efficiency by eliminating intermediate up- conversion stages and corresponding LO sources. These advantages are especially valuable for satellite communications payloads due to strict constraints on payload volume, mass, and power consumption of spacecrafts. To mitigate impairments from quadrature modulator hardware commonly experienced in direct modulation, CRC Canada has developed a novel self-calibration direct modulator technique based on RF envelope sampling and digital signal processing to drive a pre-compensation mechanism. The new technique has been successfully prototyped and tested for ground terminal applications. This paper further addresses development of a Ka-band direct modulator for high-speed on-board transmitters. Test results indicate the new technology can effectively remove degradations from carrier leakage and I-Q imbalance.
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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 | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".