Broad-band, large delay range, high precision, and variable analog delay lines for a high-frequency phased array beamformer
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
A set of prototype RF delay lines have been developed in order to meet the required bandwidth, delay accuracy, and delay range requirements for a previously developed 64 channel endoscopic phased array prototype. Each delay line is based on a planar PMN-32%PT pulse-echo transducer situated in a water bath, reflecting off a polished brass reflector. The pulse-echo transducers are mounted on individual in-house fabricated piezoelectric bimorphs, which are ‘simply’ supported. This creates an electronic delay time proportional to the distance between the single-element transducer and the reflecting surface in the water bath. When the physical length between the transducer and the reflecting surface is changed, the delay time also changes. A variable high voltage signal causes bimorph actuation and, in turn, the variable delays. The experimentally measured centre frequency and bandwidth for the pulse echo transducers was 45 MHz and 60% respectively. The pulse echo insertion loss without considering water attenuation or loss into the brass reflector was measured to be −20.8 dB, therefore one single low-noise amplifier with 20 dB gain was required for each delay line to have zero insertion loss. The signal-to-noise ratio was only decreased by 1.1dB with this amplifier in place. The total delay range measured by adjusting the bimorph voltage by +/− 80V was 1.4 µs, and the accuracy/repeatability of the pulse delay was less than 3ns. To date 16 channels of individually controlled parallel delays have been fabricated and the fabrication/testing of a full 64 channel system is ongoing.
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.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 it