Compact tri-band bandpass filter with controllable frequencies based on a novel quarter wavelength trisection stepped impedance resonator
Bibliographic record
Abstract
A compact microstrip line tri-band bandpass filter (BPF) with controllable working frequency bands is proposed in this paper. The proposed BPF is composed of two novel quarter-wavelength (λg/4) tri-section stepped impedance resonators (TSSIRs). Meanwhile, for the first time, the electrical lengths for the first three modes of this proposed λg/4 TSSIR are mathematically derived to determine the working frequency ratio. By replacing those conventional λg/4 uniform impedance resonators employed in an optimum BPF with fixed frequency ratio, the three working frequency bands in a BPF can be flexibly adjusted based on design specifications. The size of this λg/4 TSSIR is also smaller than existed λg/2 TSSIR, leading to a smaller size of the overall design. In order to verify this design approach, a tri-band bandpass filter with passbands centered at 1.0/3.5/6.0 GHz is designed, fabricated and measured. The minimum insertion loss of each passband is 0.07/0.52/1.14 dB, while the occupied size of the filter is only 31×21.5 mm2(0.17λg×0.12λg). A good symmetry for each passband is also observed in this prototype.
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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) | 0.001 | 0.001 |
| 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 | 0.001 | 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".