| εr″/εr′ | Current conduction | Field propagation |
|---|---|---|
| 0 | perfect dielectric lossless medium | |
| ≪ 1 | low-conductivity material poor conductor |
low-loss medium good dielectric |
| ≈ 1 | lossy conducting material | lossy propagation medium |
| ≫ 1 | high-conductivity material good conductor |
high-loss medium poor dielectric |
| ∞ | perfect conductor |
