400-to-800-MHz GaAs pHEMT-Based Wideband LNA for Radio-Astronomy Antenna-Array Feed
Bibliographic record
Abstract
This letter presents the design of a two-stage 400-to-800-MHz GaAs pseudomorphic high-electron-mobility transistor wideband low-noise amplifier (LNA) to upgrade an aperture synthesis radio telescope. The first stage is based on an inductive-source-degenerated amplifier topology, uses a low voltage supply, and utilizes an intrinsic input-transistor gate-drain feedback to improve the LNA bandwidth and gain. The final stage, a common-source amplifier, provides 50-Ω match and increases the gain. Employing matching via intrinsic feedback and a low-voltage supply, the LNA exhibits gain (S21) from 41.1 to 43.3 dB, a minimum input-referred 1-dB compression point of -32.8 dBm, and a noise figure from 0.26 to 0.34 dB over the 400-to-800-MHz band. A future antennaarray feed with such LNAs is expected to exhibit 18.8-26.3 K beam-referred noise temperatures. The LNA consumes 406 mW from a 1.4-V supply.
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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 | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.002 |
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".