Appendix D
Physical Constants and Material Parameters
Throughout the text we have used several physical constants, such as the velocity of light in free space. In the examples we have been using non-perfect electrically conducting metals such as copper and have used dielectric materials. For convenience, in this appendix we have grouped the physical constants used in this book and have provided a list of material properties frequently encountered.
The physical constants used frequently within this book are
- permittivity of free space: ε0 = 8.854 · 10−12 Fm−1
- permeability of free space: μ0 = 4π · 10−7 Hm−1
- velocity of light in free space: c0 = 2.998 · 108 ms−1
- impedance of free space: η0 = 376.7 ≈ 120πΩ
The electrical conductivities of some commonly used metals and liquids at room temperature are given in Table D.1.
Table D.1 Electrical conductivities of some common metals and fluids
| Material | Conductivity Sm−1 |
| aluminum | 3.816 · 107 |
| copper | 5.813 · 107 |
| gold | 4.098 · 107 |
| iron | 1.03 · 107 |
| lead | 4.56 · 106 |
| nickel | 1.449 · 107 |
| stainless steel | 1.1 · 106 |
| solder | 7.0 · 106 |
| distilled water | 2 · 10−4 |
| sea water | 4 |
The dielectric constants and loss tangents of some materials are given in Table D.2 [1–3].
Table D.2 Dielectric constants and loss tangents of some materials
| Material | Relative Permittivity εr | Loss Tangent tanδ |
| FR4 (3 GHz) | 4.28 | 0.016 |
| glass Pyrex (3 GHz) | 4.82 | 0.0054 |
| plexiglas (3 GHz) | 2.60 | 0.0057 |
| polyethylene (10 GHz) | 2.25 | 0.0004 |
| polystyrene (10 GHz) | 2.54 |
