https://en.wikipedia.org/wiki/FR-4
εr = 4.35?
https://docs.oshpark.com/services/two-layer/
εr = 4.6 @1MHz
https://www.embedded.com/print/4398951
εr = 4.45 @1GHz
- εr of the PCB: 4.45
- Thickness of the dielectric: 1.43 mm (1.5 - 2 * 0.035 Cu)
- Width of the track: 2.25 mm
- Width of the gap: 0.8 mm
http://chemandy.com/calculators/coplanar-waveguide-with-ground-calculator.htm
50 Ohm
- εr of the PCB: 4.45
- Thickness of the dielectric: 0.0762 mm (1.5 - 2 * 0.035 Cu)
- Width of the track: 2.25 mm
- Width of the gap: 0.8 mm
| Thickness | Layer | Tolerance |
|---|---|---|
| 1mil (0.0254mm) | solder resist | +/-0.2mil (0.00508mm) |
| 2.8 mil (70um) | 2 oz copper | |
| 30 mil (0.762) | FR4 core | +/-3mil (0.0762mm) |
| 2.8 mil (70um) | 2 oz copper | |
| 1mil (0.0254mm) | solder resist | +/-0.2mil (0.00508mm) |