Wavelength tunable phase-locked laser diodes for true-time delay beamforming
Bibliographic record
Abstract
Photonic true-time delay (TTD) beamforming has been considered a promising technique for wideband phased-array antenna (PAA) systems. An efficient way to achieve optical TTD beamforming is through the use of fiber Bragg grating (FBG) delay lines. In an FBG-based TTD beamforming system, a microwave signal carried by an optical carrier is required, which is usually obtained by modulating the microwave signal on the optical carrier using an external modulator. In this paper, we propose a novel approach to economically generate high-frequency microwave signals using two wavelengths from two phase-locked laser diodes through optical heterodyning. Since no optical modulator is required, the cost is significantly reduced. In addition, since the system uses only two wavelengths, the power-penalty problem caused by chromatic dispersion is minimized. In the proposed approach, the two phase-locked wavelengths are generated using an optical phase-locked loop (OPLL). A TTD beamforming system using an OPLL in combination with FBG-based delay lines to achieve tunable time delays is investigated. Experimental results are provided.
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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 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".