Broadband X-band characterization of machinable, homogeneous solids. Using the Keysight PNA-X Vector Network Analyzer and a Nicolson-Ross-Weir extraction, iEMSL measures complex permittivity, loss tangent, and (as a custom add-on) complex permeability, in support of ASTM D5568-22a.
8.2-12.4 GHz
Frequency (X-band)
±5%
Dk & Df accuracy
ASTM D5568
Method standard
5 business days
Standard turnaround
Why the WR-90 transmission line
Standards-based
Supports ASTM D5568-22a, the recognized waveguide transmission-line method.
Machinable solids
Ideal for bulk plastics, composites, ceramics, and filled materials that can be cut to the waveguide aperture.
Best for lossy and medium-loss materials
The transmission-line approach handles materials that resonator methods cannot.
Magnetic and shielding
Complex permeability (μr) and shielding effectiveness can be measured in the same X-band fixture on request.
Magnetic and shielding characterization (custom add-ons)
The same WR-90 waveguide fixture supports two custom add-ons, both quoted per job:
Complex permeability (μr)
For ferromagnetic materials and absorbers across 8.2-12.4 GHz, supporting ASTM D5568-22a.
Shielding effectiveness (SE)
EMI/RFI attenuation (±1%) for lossy, lightly doped and composite materials, within the WR-90 X-band range.
Technical specifications
| Frequency | 8.2-12.4 GHz (X-band) |
| Dielectric constant (Dk) | ±5% |
| Loss tangent (Df) | ±5% above 1×10⁻³ |
| Shielding effectiveness | ±1% |
| Temperature | Room temperature |
| Extraction | Nicolson-Ross-Weir |
Sample requirements
Aperture: 22.81 mm × 10.11 mm (slip fit)
Thickness: 1-9.7 mm
Form: solid, homogeneous, machined to the aperture with flat, parallel faces
Send three thicknesses of the same material so we can avoid the NRW divergence regions and pick the optimum for both Dk and Df.
Why we ask for three thicknesses
The Nicolson-Ross-Weir extraction becomes unstable near sample thicknesses that are integer multiples of the in-material half-wavelength, and the location of that instability depends on your material’s Dk. Loss tangent extraction is also thickness-dependent: low-loss materials need enough thickness to produce measurable attenuation, while high-loss materials need to be thin enough to keep the transmitted signal above the noise floor. Submitting three thicknesses of the same material lets us cross-check the result, avoid the divergence regions, and select the optimum thickness for both Dk and Df.
| Material class | Suggested thicknesses |
|---|---|
| Unknown / general purpose | 2, 4, 6 mm |
| Low-loss polymers (PTFE, PE) | 3, 5, 7 mm |
| Standard polymers, FR-4 substrates | 2, 3.5, 5 mm |
| High-Dk ceramics or filled composites | 1.5, 2.5, 4 mm |
| Lossy / carbon-loaded / absorbers | 1, 1.5, 2 mm |
Single samples are accepted, but Df accuracy is reduced and the result is flagged if the thickness falls near a divergence region.
What to send us
- Three samples of the same material, machined to 22.81 × 10.11 mm (slip fit)
- Thicknesses per the table above (or 2 / 4 / 6 mm if the material is unknown)
- A note if the material is lossy, anisotropic, or temperature-sensitive
- Whether you need a calibrated technical report (additional charge)
Pricing
$300 first sample
Covers Dk and Df, or shielding effectiveness. Each additional sample is $200.
Add complex permeability (μr) for +$200 per sample.
Standard turnaround 5 business days, with rush service available.
Texas A&M researchers receive 50% off listed prices.
What you receive
- Extracted Dk and Df
- Charts and tables versus frequency
- Raw data (Touchstone files) on request
- Technical report on request (additional charge)
View our example measurements. See also: SPDR, FPOR, custom characterization, all material characterization services.
Frequently Asked Questions
Why do you ask for three sample thicknesses?
The Nicolson-Ross-Weir extraction becomes unstable near thicknesses that are integer multiples of the in-material half-wavelength, and that point depends on your material’s Dk. Loss tangent extraction is also thickness-dependent. Three thicknesses let us cross-check, avoid the divergence regions, and pick the optimum for both Dk and Df.
Can I submit only one sample?
Yes, but loss tangent accuracy is reduced, and the result is flagged if the thickness happens to fall near a divergence region.
Can you machine my samples to size?
We don’t machine samples in-house, so please send them already cut to the required dimensions. For the WR-90 waveguide that’s 22.81 × 10.11 mm with flat, parallel faces. Tell us your material and target method and we’ll provide the exact dimensions and tolerances before you fabricate.
Do you measure permeability or shielding effectiveness?
Yes. The same WR-90 fixture measures shielding effectiveness (±1%) for lossy, lightly doped and composite materials, priced as a base measurement in place of Dk and Df, and complex permeability (μr) of ferromagnetic materials and absorbers across 8.2-12.4 GHz (per ASTM D5568-22a) as a +$200-per-sample add-on.
How accurate is the loss tangent?
Df is measured to ±5% above 1×10⁻³, with larger uncertainty below that. Dk is ±5% and shielding effectiveness ±1%.
Can you test at high temperature?
No, the WR-90 service is room-temperature only. For elevated-temperature dielectric data, use the SPDR (to 100 °C) or our custom high-temperature probe.
Can you handle ITAR-controlled or export-controlled work?
Yes. iEMSL accepts ITAR-controlled projects under a Technology Control Plan, administered with the Texas A&M export control office. Tell us your control requirements when you request a quote, before shipping any samples.
Ready to test your material?
From R&D to production, get accurate X-band data you can publish.