Noncontact Vital Sensing With a Miniaturized 2.4 GHz Circularly Polarized Doppler Radar
Bibliographic record
Abstract
Conventionally, in Doppler radar vital sign detection, two separate linearly polarized TX and RX antennas are used and often placed more than half wavelength away from each other to mitigate mutual coupling. However, the overall footprint of the radar system with separate TX/RX antennas may make it difficult to be integrated into compact consumer devices. In this article, a single dual circularly polarized circular patch antenna was presented to help to achieve a miniature Doppler radar system. The proposed antenna was designed, integrated, and demonstrated with a 2.4 GHz radar transceiver module, but the design method and approach could be extended to higher frequencies to help to reduce the antenna area needed for radar sensing. The designed antenna at 2.4 GHz has the largest dimension of no larger than 5 cm and TX/RX isolation of better than 30 dB, ensuring good detection sensitivity. With a low output power of 0 dBm, both respiration and heartbeat movements of human test subjects can be detected accurately.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| 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 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".