A Comparative Study of Two Wideband 8×8 Butler Matrices for Millimeter-wave bands
Bibliographic record
Abstract
In this paper, two different designs of 8×8 Butler matrix (BM) are presented and their performances in terms of size, insertion loss, and phase error are compared at 24.25 GHz to 27.5 GHz frequency band. The first design is based on aperture phase shifters while Schiffman phase shifters are used in the second design. However, both BM structures are employing aperture hybrid couplers to increase the bandwidth and are printed on a multilayer stack-up to avoid cross overs. Based on the achieved simulation results, employing Schiffman phase shifter improves the insertion loss and phase error of the Butler matrix compare to aperture phase shifter while both designs show similar size and good reflection coefficients in the desired frequency band. Moreover, by plotting the array factor of the butler matrix based on the calculated progressive phase differences between each adjacent output ports for each input port excitation, the results show that the 8×8 BM is able to produce eight different beams covering ±61° spatial angle range in the operating bandwidth.
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How this classification was reachedexpand
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 | 0.001 | 0.000 |
| 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 | 0.000 | 0.000 |
| Open science | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".