Surface Impedance Boundary Conditions under Transmit and Receive Conditions
Bibliographic record
Abstract
For an impedance boundary condition (IBC) to accurately model a physical electromagnetic problem, it becomes imperative to consider the surface impedance variation as the excitation source location is changed. Using the rigorous Green's function field solution for the grounded dielectric slab, it is shown that the surface impedance varies as the excitation source location is changed. For the transmit problem (source close to the slab surface), a Sommerfeld integral is numerically evaluated in the complex w plane, which allows one to compute the exact surface impedance at any surface point, including points near the source. The surface impedance from the exact solution is shown to agree with a numerical electromagnetic full-wave (COMSOL) solution. For the IBC to have the same field as the original grounded slab, the surface impedance should match the actual slab- and it is not a constant, but varies, especially near the source. An IBC Green's function is only possible when the surface impedance is constant. When the impedance is not constant, we obtain an exact solution by using radiation integrals on the infinite aperture. We decompose the true aperture fields from the true grounded slab problem into geometrical optics (GO) field part and the surface wave field part. This in turn allows one to compute the field solution by solving the radiation integrals over an infinite aperture. The field solution is compared with COMSOL. The results show that for a transmitting antenna the surface impedance is a relatively complicated function, compared to the receiving case. It is therefore incorrect to assume that surface impedance is simply a number, when considering transmitting antennas.
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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 | 0.001 | 0.006 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.004 | 0.003 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.025 | 0.010 |
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".