Design and analysis of the NRC Q-band receiver for ngVLA band-5
Bibliographic record
Abstract
The radio instrumentation team (RIT) at NRC’s (National Research Council Canada) Herzberg astronomy and astrophysics research center (HAA) is currently developing a dual-linear polarization, single-feed Q-band cryogenic radio astronomy receiver to develop and demonstrate important technologies needed for front-end development for the next generation very large array (ngVLA) project lead by the National Radio Astronomy Observatory (NRAO). The specific target is the ngVLA band-5 receiver, which covers the frequency range 30.5–50.5 GHz. It also serves as a technology demonstrator for component development for ngVLA bands-3, 4, and 6. The Q-band receiver system is designed to achieve a receiver noise temperature of less than 20 K over 70% of the bandwidth and better than 24 K over the complete operating bandwidth, and is compliant with the current ngVLA Band-5 receiver requirement. The receiver system consists of a cryostat with a cooled feed horn, a turnstile OMT (orthomode transducer) plus two noise couplers for calibration, two cryogenic mHEMT low noise amplifiers with noise temperature lower than 14 K, IR filters, and a vacuum window for low-loss transmission of electromagnetic fields into the cryostat.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.003 |
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".