How to select the measurement methods
Selecting Dielectric Constant Measurement Method
Select from specimens
Title  Ref. No.  Frequency  ex) Sample  Feature  
1.  Open type Resonator method  DPS03  18GHz~110GHz  Multilayer material Printed board Film(Ultra thin film) Powder Sheet(Board) Radome cover Ceramics Dielectric resonator Ferroelectric 
Resonator method series For low tan delta materials High accuracy Point frequency 
2.  TMmode Open Resonator method  DPS18  200MHz~10GHz  
3.  TEmode Open Resonator method  DPS19  10GHz~40GHz  
4.  Strip line type Resonance method  DPS50  800MHz~14GHz  
5.  Micro strip line type Resonance method  DPS01  800MHz~14GHz  
6.  Circular Disk type Resonator method  DPS51  3GHz~70GHz  
7.  LC Resonator method  DPS26  10MHz, 50MHz, 100MHz  
8.  Parallel conductor plate
type Dielectric resonator method 
DPS14  3GHz~26.5GHz  
9.  Frequency change method  DPS10  2.6GHz~110GHz  Multilayer material Printed board Powder Board Phantom Wave absorber Radome cover 
Frequency change method series For low tan delta and thick materials 
10.  Frequency change method Coaxial tube and waveguide type  DPS09  10MHz~60GHz  
11.  Probe type (open mode)  DPS16  30MHz~90GHz  Multilayer material Sheet(Board) Phantom material Wave absorber Noise suppression sheet Soil Concrete, Asphalt Radome cover Fruit, Vegetable Liquid 
S parameter method series For highr tan delta materials Wide coverage of frequency Permeability is measureable (12, 13. 14) 
12.  Probe type (short mode)  DPS25  100kHz~10GHz  
13.  Coaxial Tube and Waveguide Type Sparameter method  DPS08  12MHz~40GHz  
14.  Free space type Sparameter method  DPS24  2.6GHz~110GHz  
15.  Free space Angle of incidence change type Sparameter method  DPS22  2.6GHz~110GHz  
16.  Propagation Delay Mode Cut Back Type Coaxial Tube Method 
DPS05  45MHz~40GHz  
17.  Capacitance method  DPS17  1Hz~1GHz  Multilayer material Printed board Film(Ultra thin film) Sheet(Board) Phantom material Noise suppression sheet Liquid Ceramics Semiconductor 
Capacitance method series For low frequency High accuracy Wide coverage of frequency 
18.  MOSFET structure semiconductor depletion layer And just below the gate electrode dielectric film 
DPS48  20Hz~2MHz  
19.  Ellipsometry method  DPS02  26.5~110GHz  Ellipsometry method Dielectric cnstant, permeability measurement 
Select from measurement frequency, dielectric constant, dielectric loss tangent
Select from measurement frequency, dielectric constant, dielectric loss tangentSelect from measurement frequency, method, specimen size
Select from measurement frequency, method, specimen sizeSelect from specific request
The following table is based on FAQ. Please contact us for details.
When you want to measure an ultra thin film on the printed board with high accuracy (measurement of film, multilayer material) 
»  Perturbation method 
When your sample is so thin it falls apart without supporting medium (measurement of film, multilayer material) 
»  Perturbation method 
When high accuracy is the priority (εr' ±1% tanδ ±3%)  »  Perturbation method 
When you only have a sample as small as 1mm  »  Probe method 
When you want to measure it in high accuracy by superhigh frequency. (20GHz  110GHz) 
»  Resonance method resonator open type 
When you want to measure it by superlow frequency.(10μHz  10Hz)  »  Capacitance method 
When you want to measure liquid  »  Probe method 
When you want to measure powder  »  Probe method 
When you want to measure volatile substance such as gasoline  »  Probe method 
When you want to change the measurement temperature  »  Capacitance method 
When you want to sweep frequency and obtain rough result, accuracy is less importan (εr' ± 7% tanδ ± 10%)  »  Sparameter method 
When you do not want your sample cut or reshaped (Nondestructive)  »  Resonance method micro strip line type 
When you want the process as simple as possible  »  Probe method 
When you want to measure dielectric constant, dielectric loss tangent,and permeability at once  »  Sparameter method 
Introduction to KEYCOM's measurement methods
Resonance method
Hiroke Suzuki of Keycom articipated in the drafting of the standard as a member of the committee, and it was officially standardized in the spring of 2004.
Open resonator method for sheet and ultra thin sheet dielectric constant and dielectric loss tangent(millimeterwave) measurement system [DPS03]  
KEYCOM’s ultrathin sheet measurement system employs the FabryPerot resonator, a liner optical resonator which consists of two highly reflecting mirrors, which combines the high measurement accuracy in the millimeter wave range and simplicity of installing the specimens. It is also ideal for specimens with low tanδ. This method was presented at 2005 IEEE Instrumentation and Measurement Technology Conference Ottawa Ontario, CANADA. 


Resonance method strip line type for sheet dielectric constant and dielectric loss tangent measurement system [DPS50] 
In frequency range from 800MHz to 14GHz, it is the measurement system of εr'and tanδ , for sheet material of small dielectric loss tangent and 140 εr'. We follow the ASTMD338075 Standard method of Test for Permittivity(Dielectric Constant) and Dissipation Factor of PlasticBased Microwave Circuit Substrates and IPCL125 Specification for Plastic Substrates, Clad or Unclad, for High Speed / High Frequency Interconnections. 
Circular Disk Resonator Type Dielectric Constant and Dielectric Loss Tangent(Dk/Df) Measurement System [DPS51] 
The system is for measuring εr' and tan δ of sheet materials with relatively small dielectric loss whose εr' is approximately 1.05 to 10 at frequencies from 3 GHz to 70 GHz. KEYCOM made presentation about the measurement method at IEEE IMS in 2012. [References] Hirosuke Suzuki, Masato Inoue "Complex Permittivity MultiFrequency Measurements for Dielectric Sheets Using a Circular Disk Resonator". 2012 IMS2012 THPB1 
Resonance method micro strip line type for sheet and ultra thin sheet dielectric constant and dielectric loss tangent measurement system [DPS01] 
The system can measure εr and tanδ of materials with relatively small dielectric loss and ultrathin sheet materials with εr approximately from 1 to 40 at frequencies from 800MHz to 14GHz, and also measure ultrathin dielectric sheets. It conforms to ASTMD3380 Standard method of Test for Permittivity (Dielectric Constant) and Dissipation Factor of PlasticBased Microwave Circuit Substrates, and IPCL125 Specification for Plastic Substrates, Clad or unclad, for High Speed/High Frequency Interconnections. 
Perturbation method
Perturbation method specimenhole closed type, cavity resonance mode, for ultra thin sheet dielectric constant and dielectric loss tangent measurement system [DPS18]  
KEYCOM’s high precision perturbation method enables you to measure dielectric constant (permittivity, εr) and dielectric loss tangent (tan δ) of such specimens as multilayered structure, ultrathin film or ferroelectric materials in the microwave region. KEYCOM refined the conventional perturbation method that was JISstandardized in 1992 (JISC2565) by closing the hole into which the specimen is inserted with metal, and the new method is also compliant with ASTMD2520. 


Propagation delay method
Propagation delay mode cut back type coaxial tube method dielectric constant and dielectric loss tangent measurement system [DPS05] 
In the 45 MHz40 GHz frequency range, this system measures permittivity(dielectric constant, εr) and dielectric loss tangent(tan δ) of liquids having εr of approximate 1.05500. It can also estimate the voltage dependence of εr and tan δ for samples such as liquid crystals by applying a bias voltage during the measurement. 
Propagation delay mode cut Back type coplanar line method dielectric constant and dielectric loss tangent(Dk/Df) [DPS07] 
In the 45 MHz40 GHz frequency range, this system measures dielectric constant/permittivity and dielectric loss tangent of the materials which have dielectric constant of approximate 1.05500. Especially it greatly contributes to large loss specimens. 
Propagation delay mode Cut Back type stripline method dielectric constant and dielectric loss tangent measurement system(Dk/Df) [DPS15] 
This is a measurement device and system to measure εr and tan δ of a liquid at frequencies from 500MHz to 65GHz, where the liquid covers the coplanar line with a thickness of about 0.2mm. Equipped with electromagnetic simulation software for the coplanar line, the system induces the εr and tanδ of the liquid from the effective relative permittivity and effective tanδ of the liquid and the dielectric material that forms the coplanar line. By applying a bias, the voltage dependence of εr and tanδ of liquid crystal can also be evaluated. 
Probe method
Open Mode Probe Method Dielectric Constant and Dielectric Loss Tangent Measurement System(Dk/Df) [DPS16]  
KEYCOM offers probes with different outside diameters of 1.2mmφ, 2.2mmφ, 3.6mmφ to meet specific measurement requirements.

SParameter Method, Probe (Short) Type Relative Permittivity, Dielectric Loss Tangent (Dk/Df), Measurement System [DPS25] 
・Possible to measure from low frequency (100KHz) to high frequency (10GHz). ・Solids and liquids can be used as samples. ・The electric field is perpendicular to the sample surface, which is the same direction as that of microstrip lines and strip lines. ・The electric field is perpendicular to the sample surface, the same direction as the microstrip line and strip line. 
S parameter method
SParameter Method,Reflection and Transmission Mode, Coaxial Tube and Waveguide Type Dielectric Constant, Dielectric Loss Tangent, Permeability Measurement System [Permittivity, Dk/Df] [DPS08] 
KEYCOM provides Sparameter method measurement systems in two modes, the reflection mode and the transmission mode, to address the individual purposes.Both modes measure the complex permittivity (εr) and complex permeability (μr) at the same time, and the proper usage is as follows. The optional software DMP70 calculates the absorption ratio and the reflection ratio of electromagnetic absorbers based on the complex εr and complex μr. 
SParameter Method, Free Space Type Dielectric Constant, Dielectric Loss Tangent, Permeability (μ'/μ''), Transmission attenuation, Electric wave absorptance Millimeter wave / Microwave Measurement equipment [εr', tanδ / Dk, Df] [DPS24] 
Unlike the coaxial tube and waveguide types, the sample is not placed inside the fixture, so errors due to air gaps do not occur. It also provides practical data when there are uneven characteristics or unevenness depending on the location of the sample. A lens is attached to the antenna, allowing the sample to be measured in a plane wave while remaining compact. The measurement is performed by connecting a vector network analyzer and a computer to the test fixture and observing the Sparameters S21 and S11. 
Capacitance method
Capacitance Method:Dielectric Constant and Dielectric Loss Tangent Measurement System(Dk/Df) for Flat Plate, Liquid, Gel, UltraThin Film, Thinfilm Compounds [DPS17] 
KEYCOM’s capacitance method/system is ideal for dielectric constant and dielectric loss tangent measurement of flat plane, liquid, or gel and capable of taking measurements in the temperature range from liquid nitrogen or 70 to 400 degrees Celsius. Different types of electrodes are available for specific states of specimens; DPT009 for plate, thin film, gel, DPT012, DPT013050 and DPT013200 for liquid, and DPT2141 for ceramic insulators. 
Incident Angle Changing Method
Angle of Incidence Change Method Dielectoric Constant, Dielectric Loss Tangent, Permeability(Dk/Df) Measurement System [DPS22] 
The incident angle dependence of the reflection attenuation and the reflection phase angle are measured for TE and TM waves.
The complex relative permittivity and complex permeability are obtained by inverse estimation from these measurements. Unlike the coaxial tube and waveguide types, the sample is not placed inside the fixture, so there is no air gap error. Since a lens is attached to the antenna, the sample can be measured as a plane wave despite its compact size, and high measurement accuracy can be obtained. Radio wave emitted from the antenna is a parallel beam, so the sample can be made smaller.In addition, εr' and μr can be obtained for each frequency. *Measurements can be made without an anechoic chamber. 
Transmission Attenuation Method
Millimeter Wave, Permittivity, Dielectric Loss Tangent and Transmission Attenuation Measurement System [RTS02]  
The relative dielectric constant and tan δ are obtained from the relationship between the frequency and the transmission attenuation when millimeter waves pass through a flat plate.
👉Note: The higher the frequency, the smaller the sample can be measured. Using a standard vector network analyzer and applying GATE beyond the lens after calibration, transmission attenuation can be measured with a resolution of 0.1 dB and dielectric constant of 0.01.Scalar network analyzers and synthesized sweepers can also be used. 
Microwave, Permittivity, Dielectric Loss Tangent and Transmission Attenuation Measurement System [RTS04]  
The relative dielectric constant and tan δ are obtained from the relationship between the frequency and the transmission attenuation when millimeter waves pass through a flat plate.
👉Note: The higher the frequency, the smaller the sample can be measured. Using a standard vector network analyzer and applying GATE beyond the lens after calibration, transmission attenuation can be measured with a resolution of 0.1 dB and dielectric constant of 0.01.Scalar network analyzers and synthesized sweepers can also be used. 
Microwave, Vertical Type Permittivity (Dielectric constant), Dielectric Loss Tangent and Transmission Attenuation Measurement System [RTS03] 
The measurement frequency range of this system is from 26.5 GHz to 110 GHz. 
Other measurement methods
Parallel Conductor Plate Type, Dielectric Resonator Method, Dielectric Constant and Dielectric Loss Tangent Measurement System(Dk/Df) [DPS14] 
This is a highprecision measurement system for microwave band εr and tanδ, mainly for lowloss materials. A cylindrical sample is used. The measurement method is specified in JIS R 1627. 
Ellipsometry Method, Dielectric Constant and Permeability Measurement System(Dk/Df) [DPS02] 
Because of scalar measurement, the system does not require an expensive vector network analyzer. By measuring the amplitude ratio and phase difference between the TE and TM waves of the reflection coefficient, the complex relative permittivity and complex permeability can be determined. Unlike the coaxial tube and waveguide types, the sample is not placed inside the fixture, so errors due to air gaps do not occur. A lens is attached to the antenna, making it compact and allowing the sample to be measured in a plane wave. In addition, the sample can be set near the antenna, making the sample smaller. In addition, εr and μr can be obtained for each frequency. 
Cutoff Cylinder Waveguide For Millimeterwave measurement of Relative Permittivity and Dielectric Loss Tangent (εr', tanδ) [DPS20] 
The cutoff cylindrical waveguide is used for measuring εr and tanδ for lowloss dielectric substrates, mainly in millimeterwave circuits. 