Microwave Photonic Hilbert Transformer Based on a Single Passband Microwave Photonic Filter for Simultaneous Channel Selection and Signal Processing
Bibliographic record
Abstract
A microwave photonic Hilbert transformer (MPHT) with a single passband and wide frequency tunable range based on a single passband microwave photonic filter (MPF) is proposed and experimentally demonstrated. The MPF is implemented using a broadband light source and a Mach-Zehnder interferometer (MZI) incorporating a phase modulator in one arm and a phase-shifted chirped fiber Bragg grating in the other arm. The optical signal at the output of the MZI is sent to a dispersion compensating fiber, and then, detected at a photodetector. The overall operation corresponds to a single passband MPF with a π phase-shift at the center of the passband, which has the frequency response corresponding to a microwave Hilbert transformer. The central frequency of the MPHT can be continuously tuned by tuning the length difference between the two arms of the MZI using a tunable delay line. A theoretical analysis is performed, which is verified by simulations and an experiment. In the experiment, an MPHT with a bandwidth of 1.70 GHz and a continuously tunable frequency from 5 to 15 GHz is demonstrated. The proposed MPHT can find applications in multi-channel microwave communications systems, where simultaneous channel selection and Hilbert transformation are needed.
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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 | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".