Improving Compact Short Backfire Antenna Gain and Cross-Polarization Using Choke and Ring Cavity Loading
Bibliographic record
Abstract
We present two designs that improve the gain and cross-polarization performance of the waveguide-fed short backfire (SBF) antenna by introducing a choke (SBF-2) and by loading the cavity with a metallic ring feature (SBF-2-Ring). A series of parametric simulation studies on antenna dimensions provides information on how to improve the antenna gain and cross-polarization performance while simultaneously extending the impedance bandwidth. For SBF-2, the peak gain was 16.6 dBi, the minimum cross-polarization ratio was −23.8 dB, and the maximum impedance bandwidth was 27.3%, with a gain bandwidth of 19.2%. For SBF-2-Ring, the peak gain was 15.8 dBi, the minimum cross-polarization ratio was −29.1 dB, and the maximum impedance bandwidth was 43.5%, with a gain bandwidth of 31.8%. The concepts were verified by designing, fabricating, and testing two prototypes in the microwave C-band. Excellent agreement between simulation and measurement was achieved. The measured gain for SBF-2-Ring was >14 dBi for 4.7–6.2 GHz and the worst case cross polarization in the diagonal plane was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$< -22$ </tex-math></inline-formula> dB for 5.3–5.8 GHz. Cross-polarization in the principal planes has significantly greater bandwidth and the worst case analysis is presented to give limitations on the performance.
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 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 | 0.001 | 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 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".