A Sub-mW Integrating Mixer SAR Spectrum Sensor for Portable Cognitive Radio Applications
Bibliographic record
Abstract
A low power mixed-signal integrating mixer successive approximation register (SAR) architecture is proposed for direct spectrum estimation in portable transceivers targeting IEEE 802.22 wireless regional area network cognitive radio applications. The integrating mixer SAR implements the short-time Fourier transform in the analog domain and digitizes its amplitude at the end of the integration period. The architecture consists of an array of folded double balanced mixers connected to a common subset of binary-weighted capacitive loads. Current domain windowing is applied in the first stage followed by mixing, integration and analog-to-digital conversion (ADC) in the second stage. Windowing sets the detection bandwidth and provides flexible low pass filtering while a load capacitor array enables integration with programmable time constant and acts as the sampling capacitors of a SAR ADC. A prototype chip is fabricated in IBM's 0.13μm CMOS process. The measured results indicate an average dynamic range of 27.9-25.7 dB over a frequency range of 0.05-1.25 GHz, while consuming 0.88 mW from 1.1/1.2 V supplies.
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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 | 0.001 |
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".