DAK-TL-P²: 200 MHz – 20 GHz

Fast and Precise Dielectric and Magnetic Measurements of Thin Layers


The DAK-TL-P² system was developed for measuring the dielectric and magnetic properties of thin material layers in the millimeter and sub-millimeter range. The TL-P² is based on the DAK-3.5 probe technology, but with modified algorithms to take into account the limited sample size. The second open coaxial probe integrated into the sample platform sandwiches the material under test. In this configuration, both reflection and transmission are measured, and the two complex quantities are used to calculate the relative permittivity and permeability. The frequency range is that of the DAK-3.5 probe, 200 MHz – 20 GHz. The system can be be converted to TL-P mode for dielectric measurements only by covering the open coaxial probe on the sample platform with a metallic plate (provided). The system is fully automated and software controlled: the automated sample platform brings the material under test to the probe and measures the sample thickness with micrometer precision. The applied force can be precisely controlled to enable high measurement repeatability for soft samples such as leather or soft plastic.

  • Measurement of raw printed circuit board materials over a broad frequency range
  • Dielectric and magnetic characterization of microwave substrates and antenna holders
  • Measurement of magnetic dielectric materials for electronic components, e.g., capacitors, coils, and resonators
  • Measurement of shielding efficiency


1 DAK-TL-P² Base System
1 DAK-3.5-TL Probe Beam (200 MHz – 20 GHz)
2 High Precision 26 GHz Cable (PC3.5 F connectors, 0.5 and 1 m long)
1 Set of Calibration Standards
1 Set of Reference Materials and Gauge Blocks
1 Metal Petri-Dish for Liquids
1 Metallic Cover for 1-probe configuration (the system is used as DAK-3.5TL-P)
1 VNA Platform
1 DAK-TL Measurement Software V2 incl. Manual

Base System

The DAK-TL-P² Base System accommodates the automated sample platform with built-in thickness measurement, the force sensor, and the controlling electronics. The Base System is connected to the PC via USB. The Base System is fully automated and software controlled. The sample is to be placed on the sample platform which brings it to the probe and measures the sample thickness with micrometer precision. The second open coaxial probe is embedded in the sample platform. With this transmission is measured in addition to reflection. Only the DAK-3.5-TL Probe Beam can be attached. By covering the open coaxial probe embedded in the sample platform with a metallic plate, the DAK-TL-P² Base System can be used as DAK-TL-P Base System.

Thickness Measurement Range: 0.1 mm – 10 mm
Thickness Measurement Precision: <0.003 mm (preliminary specification)
Force Measurement Range: 0 – 1000 N
USB Connector: Type B
Weight: ~16 kg
Operating Temperature Range: 10 – 50 °C

Probe Beam

Connector Type: 3.5 mm male
Outer Conductor Inside Diameter: 3.5 mm
Inner Conductor Diameter: 0.93 mm
Flange Diameter: 48 mm
Dielectric Bead Material: Eccostock
Flange: Stainless steel
Beam Dimensions: 40 × 30 × 350 mm
Robustness: High resistance to corrosive materials
Automation: Mechanical positioning of open coaxial probe


Calibration is performed according to SPEAG's high-quality standards; ISO/IEC 17025 scope extension is in progress.


The software is embedded in the same graphical user interface as the DAK packages  to deliver a similar user experience.

VNA Compatibility

DAK-TL-P² requires a 2-port VNA: please see our list of currently supported compatible VNA models. Attractive system packages configured with VNAs from Rohde & Schwarz are available upon request.


The release of DAK-TL-P² is anticipated in 2019Q3. Please ask for a quotation from your nearest SPEAG representative or contact us at