QDielectricLoss =
Loss Tangent =
Dielectric Loss = 
Values presented here are relative dielectric constants (relative permittivities).
As indicated by er = 1.00000 for a vacuum, all values are relative to a vacuum.
Multiply by ε0 = 8.8542 x 10-12 F/m (permittivity of
free space) to obtain absolute permittivity. Dielectric constant is a measure of the
charge retention capacity of a medium.
In general, low dielectric constants (i.e., Polypropylene) result in a "fast" substrate
while large dielectric constants (i.e., Alumina) result in a "slow" substrate.
The dielectric loss tangent is defined by the
angle between the capacitor's impedance vector and the negative reactive axis, as illustrated
in the diagram to the right. It determines the lossiness of the medium. Similar to dielectric
constant, low loss tangents result in a "fast" substrate while large loss tangents result
in a "slow" substrate.
Beware that the exact values can vary greatly depending on the particular manufacturer's
process, so you should seek out data from the manufacturer for critical applications.
The dielectric constant can be calculated using: ε = Cs / Cv , where Cs
is the capacitance with the specimen as the dielectric, and Cv is the capacitance with
a vacuum as the dielectric.
The dissipation factor can be calculated using: D = tan
δ = cot θ = 1 / (2π f RpCp) , where δ is the loss
angle, θ is the phase angle, f is the frequency, Rp is the
equivalent parallel resistance, and Cp is the equivalent parallel capacitance.
Note: All values can vary by very large amounts depending on the specific material.
Check with the MatWeb.com
website for more details.
| ABS (plastic), Molded |
2.0 - 3.5 |
400 - 1350 |
0.00500 - 0.0190 |
171 - 228 |
| Air (STP, @900 kHz) |
1.00058986 |
30 - 70 |
|
|
| Alumina - 96%
- 99.5% |
10.0 9.6 |
|
0.0002 @ 1 GHz 0.0002 @ 100 MHz 0.0003 @ 10 GHz |
|
| Aluminum Silicate |
5.3 - 5.5 |
|
|
|
| Bakelite |
3.7 |
|
|
|
| Bakelite (mica filled) |
4.7 |
325 - 375 |
|
|
| Balsa Wood |
1.37 @ 1 MHz 1.22 @ 3 GHz |
|
0.012 @ 1 MHz 0.100 @ 3 GHz |
|
| Beeswax (yellow) |
2.53 @ 1 MHz 2.39 @ 3 GHz |
|
0.0092 @ 1 MHz 0.0075 @ 3 GHz |
|
| Beryllium oxide |
6.7 |
|
0.006 @ 10 GHz |
|
| Butyl Rubber |
2.35 @ 1 MHz 2.35 @ 3 GHz |
|
0.001 @ 1 MHz 0.0009 @ 3 GHz |
|
| Carbon Tetrachloride |
2.17 @ 1 MHz 2.17 @ 3 GHz |
|
<0.0004 @ 1 MHz 0.0004 @ 3 GHz |
|
| Diamond |
5.5 - 10 |
|
|
|
| Delrin (acetyl resin) |
3.7 |
500 |
|
180 |
| Douglas Fir |
1.9 @ 1 MHz |
|
0.023 @ 1 MHz |
|
| Douglas Fir Plywood |
1.93 @ 1 MHz 1.82 @ 3 GHz |
|
0.026 @ 1 MHz 0.027 @ 3 GHz |
|
| Enamel |
5.1 |
450 |
|
|
| Epoxy glass PCB |
5.2 |
700 |
|
|
| Ethyl Alcohol (absolute) |
24.5 @ 1 MHz 6.5 @ 3 GHz |
|
0.09 @ 1 MHz 0.25 @ 3 GHz |
|
| Ethylene Glycol |
41 @ 1 MHz 12 @ 3 GHz |
|
-0.03 @ 1 MHz 1 @ 3 GHz |
|
| Formica XX |
4.00 |
|
|
|
| FR-4 (G-10) - low resin
- high resin |
4.9 4.2 |
|
0.008 @ 100 MHz 0.008 @ 3 GHz |
|
| Fused quartz |
3.8 |
|
0.0002 @ 100 MHz 0.00006 @ 3 GHz |
|
| Fused silica (glass) |
3.8 |
|
|
|
| Gallium Arsenide (GaAs) |
13.1 |
|
0.0016 @ 10 GHz |
|
| Germanium |
16 |
|
|
|
| Glass (Corning 7059) |
5.75 |
|
0.0036 @ 10 GHz |
|
| Glass (lead silicate) |
7 - 14 |
|
(Table 2: LS30-LS32) |
|
| Glass, Crushed / Powdered (Corning 7070) |
4.6 |
|
0.000600 |
924 |
| Gutta-percha |
2.6 |
|
|
|
| Halowax oil |
4.8 |
|
|
|
| High Density Polyethylene (HDPE), Molded |
1.0 - 5.0 |
475 - 3810 |
0.0000400 - 0.00100 |
158 - 248 |
| Ice (pure distilled water) |
4.15 @ 1 MHz 3.2 @ 3 GHz |
|
0.12 @ 1 MHz 0.0009 @ 3 GHz |
|
| Kapton® Type 100
Type 150 |
3.9 2.9 |
7400 4400 |
|
500 |
| Kel-F |
2.6 |
|
|
|
| Lexan® |
2.96 |
400 |
|
275 |
| Lucite |
2.8 |
|
|
|
| Mahogany |
2.25 @ 1 MHz 1.88 @ 3 GHz |
|
0.025 @ 1 MHz 0.025 @ 3 GHz |
|
| Mica Mica, Ruby |
4.5 - 8.0 5.4 |
3800 -5600 |
|
|
| Micarta 254 |
3.4 - 5.4 |
|
|
|
| Mylar® |
3.2 |
7000 |
|
250 |
| Neoprene |
6 - 9 |
600 |
|
|
| Neoprene rubber |
6.26 @ 1 MHz 4 @ 3 GHz |
|
0.038 @ 1 MHz 0.034 @ 3 GHz |
|
| Nomex® |
|
800 |
|
450 |
| Nylon |
3.2 - 5 |
400 |
|
280 |
| Oil (mineral, squibb) |
2.7 |
200 |
|
|
| Paper (bond) |
3.0 |
200 |
|
|
| Paraffin |
2-3 |
|
|
|
| PEEK™ 450G Polymer (@23 °C, 100 MHz) |
3.2 |
~900 |
0.003 |
|
| Phenolica (glass-filled) |
5 - 7 |
|
|
|
| Phenolics (cellulose-filled) |
4 - 15 |
|
0.03 @ 100 MHz |
|
| Phenolics (mica-filled) |
4.7 - 7.5 |
|
|
|
| Plexiglass® |
2.2 - 3.4 |
450 - 990 |
|
|
| Polyethylene LDPE/HDPE |
2.26 @ 1 MHz 2.26 @ 3 GHz |
450 - 1200 |
0.0002 @ 100 MHz 0.00031 @ 3 GHz |
170 |
| Polyamide |
2.5 - 2.6 |
|
|
|
| Polycarbonate, Molded |
2.8 - 3.4 |
380 - 965 |
0.000660 - 0.0100 |
239 - 275 |
| Polypropylene |
2.2 |
500 |
|
250 |
| Polystyrene |
2.5 - 2.6 |
500 |
0.0001 @ 100 MHz 0.00033 @ 3 GHz |
|
| Polyvinylchloride (PVC) |
3 |
725 |
|
140 |
| Porcelain |
5.1 - 5.9 |
40 -280 |
|
|
| Pyrex glass (Corning 7740) |
5.1 |
335 |
|
|
| Quartz (fused) |
4.2 |
150 - 200 |
|
|
| RT/Duroid 5880 (go to Rogers) |
2.20 |
|
|
|
| Rubber |
3.0 - 4.0 |
150 - 500 |
|
170 |
| Ruby |
11.3 |
|
|
|
| Silicon |
11.7 - 12.9 |
100 - 700 |
0.005 @ 1 GHz 0.015 @ 10 GHz |
300 |
| Silicone oil |
2.5 |
|
|
|
| Silicone RTV |
3.6 |
550 |
|
|
| Soil (dry sandy) |
2.59 @ 1 MHz 2.55 @ 3 GHz |
|
0.017 @ 1 MHz 0.0062 @ 3 GHz |
|
| Soil (dry loamy) |
2.53 @ 1 MHz 2.44 @ 3 GHz |
|
0.018 @ 1 MHz 0.0011 @ 3 GHz |
|
| Steatite |
5.3-6.5 |
|
|
|
| Strontium titanate |
233 |
|
|
|
| Teflon® (PTFE) |
2.0 - 2.1 |
1000 |
0.00028 @ 3 GHz |
480 |
|
Tefzel® (1 kHz - 3 Ghz) |
2.6 - 2.3 |
|
0.0007 - 0.0119 |
300 |
| Tenite |
2.9 - 4.5 |
|
|
|
| Transformer oil |
4.5 |
|
|
|
| Vacuum (free space) |
1.00000 |
|
|
|
| Valox® |
|
1560 |
|
400 |
| Vaseline |
2.16 |
|
0.00004 @ 0.1 GHz 0.00066 @ 3 GHz |
|
| Vinyl |
2.8 - 4.5 |
|
|
|
| Water (32°F) (68°F)
(212°F) |
88.0 80.4 55.3 |
80 |
0.04 @ 1 MHz 0.157 @ 3 GHz |
|
| Water (distilled) |
76.7 - 78.2 |
|
0.005 @ 100 MHz 0.157 @ 3 GHz |
|
| Wood |
1.2 - 2.1 |
|
0.04 @ 0.1 GHz 0.03 @ 3 GHz |
|
Supplemental information provided by website visitor James S.
for complex dielectric:
The dielectric constants at the top of [this] page are reminiscent of the propagation
constants given by Roald K. Wangsness, Electromagnetic Fields, 2nd Ed., John Wiley &
Sons, New York, 1986, p. 383, Eq. (24-42) and (24-43). The sixth equation given on the
web page is correct. That equation, as given by P. Hoekstra and A. Delaney in Dielectric
properties of soils at UHF and microwave frequencies,
J. Geophys. Res., v. 79, 10 Apr 1974, p. 1699, "... is written as
K*(ω) = K'(ω) - iK"(ω) , where
K'(ω) is the dielectric constant and
K"(ω) is the dielectric loss factor.
Hence,
Related Pages on RF Cafe
- Coaxial Cable
Specifications
- Capacitor Dielectrics & Descriptions
- Dielectric Constant, Strength, &
Loss Tangent
- Conductor Bulk Resistivity & Skin
Depths
- Coaxial Cable Equations
-
Coaxial Cable Specifications
-
Coaxial Cable Vendors
- Coaxial Resonator
- Skin Depth Calculator
-
Coaxial Connector Usage Chart
Note: Thanks to Gareth for correcting the omission of a square
root sign in the dielectric equations.
Thanks to Craig B. for correcting the loss tangent for Teflon (0.00028 rather than 0.0028).
