NIST Calibration Services: RF, Microwave and Millimeter-Wave Measurements

Electromagnetic Measurements

RF, Microwave and Millimeter-Wave Measurements

Thermistor Detectors

Technical Contacts:
Ronald A. Ginley
Tel: 303/497-3634
E-mail: rginley@boulder.nist.gov

Thomas P. Crowley
Tel: 303/497-4133
E-mail: crowley@boulder.nist.gov

Puanani L. DeLara
Administration and Logistics
Tel: 303/497-3753
Fax: 303/497-7592
E-mail: calibration@boulder.nist.gov

Do not ship instruments or standards to the mailing address listed below. Contact the technical staff for the shipping address.

Mailing Address:
National Institute of Standards and Technology
M.C. 818.01
325 Broadway
Boulder, CO 80305-3328

Service ID Number	Description of Services	Fee ($)
The following tests are for 50 thermistor and thermoelectric detectors with coaxial connectors.
61100S	Measurement setup charge (applies to all coaxial power measurements-one setup charge for multiple detectors with the same connectors and frequencies ¹ )	2730
61110S	Coaxial Detectors in the Frequency Range from 0.1 MHz to 10 MHz	3172
61120S	Coaxial Detectors at User Selected Frequencies in the Appropriate Frequency Range for the Connector Type ² . Up to 20 Frequency Points	3431
61121S	Coaxial Detectors at User Selected Frequencies in the Appropriate Frequency Range for the Connector Type ² . Up to 20 to 40 Frequency Points	3753
61122S	Coaxial Detectors at User Selected Frequencies in the Appropriate Frequency Range for the Connector Type ² . 40 to 120 Frequency Points	4074
61123S	Coaxial Detectors at User Selected Frequencies in the Appropriate Frequency Range for the Connector Type ² . More than 120 Frequency Points	4844
61137S	NIST Model CN Coaxial Detectors at 21 Frequencies within the Frequency Range of 50 MHz to 18 GHz	8228
61138S	NIST Model CN Coaxial Detectors at Single Customer Selected Frequency within the Frequency Range of 50 MHz to 18 GHz	52
The following tests are for thermistor detectors with waveguide flanges.
61140S	Measurement setup charge (applies to all waveguide power measurements EXCEPT WR15-one charge for multiple detectors with the same connectors and frequencies ¹ )	5296
61141S	Measurement setup charge (applies to all WR15 waveguide power measurements-one charge for multiple detectors with the same connectors and frequencies ¹ )	4105
61142S	Rectangular Waveguide Detectors with WR90 Flanges ²	3535
61143S	Rectangular Waveguide Detectors with WR62 Flanges ²	3535
61144S	Rectangular Waveguide Detectors with WR42 Flanges ²	3535
61145S	Rectangular Waveguide Detectors with WR28 Flanges ²	3718
61146S	Rectangular Waveguide Detectors with WR22 Flanges ²	4177
61147S	Rectangular Waveguide Detectors with WR15 Flanges ²	6470
61148S	Rectangular Waveguide Detectors with WR10 Flanges ²	7504
Miscellaneous Tests
61190S	Special Microwave and RF Power Measurement Services, by Prearrangement	At Cost
¹ Only one setup charge is necessary for multiple detectors sent in at the same time with the same connector type and measurement frequencies.

Fees are subject to change without notice.

² Measurement Frequencies:

Connector Type or Waveguide Flange Measured	Typical Frequencies for Power Measurements (if additional frequencies not covered in this list are required, there may be an additional charge-call for information)
Type-N	0.1 MHz to 1.0 MHz by 0.1 MHz steps
	1.0 MHz to 10.0 MHz by 1.0 MHz steps
	10.0 MHz to 100.0 MHz by 10.0 MHz steps
	100.0 MHz to 1.0 GHz by 50.0 MHz steps
	1.0 GHz to 18 GHz by 0.2 GHz steps (preferred)
	Older Type-N Frequencies are still supported but not preferred
	1.0 GHz to 2.0 GHz by 0.05 GHz steps
	2.0 GHz to 4.0 GHz by 0.1 GHz steps
	4.0 GHz to 12.4 GHz by 0.2 GHz steps
	12.5 GHz to 18.0 GHz by 0.25 GHz steps
GPC7	10.0 MHz to 100.0 MHz by 10.0 MHz steps
	100.0 MHz to 1.0 GHz by 50.0 MHz steps
	1.0 GHz to 18 Ghz by 0.2 GHz steps (preferred)
	Older 7 mm Frequencies are still supported but not preferred
	1.0 GHz to 2.0 GHz by 0.05 GHz steps
	2.0 GHz to 4.0 GHz by 0.1 GHz steps
	4.0 GHz to 12.4 GHz by 0.2 GHz steps
	12.5 GHz to 18.0 GHz by 0.25 GHz steps
3.5 mm	0.05, 0.1 GHz, 0.2 GHz to 33.0 GHZ by 0.2 GHz steps and 26.5 GHz
2.92 mm	0.05, 0.1 GHz and 0.2 GHz to 40 GHz by 0.2 GHz steps
2.4 mm	0.05, 0.1 GHz and 0.2 GHz to 50 GHz by 0.2 GHz steps
WR90	8.2 GHz to 12.4 GHz by 0.2 GHz steps
WR62	12.4 GHz and 12.5 GHz to 18.0 GHz by 0.25 GHz steps
WR42	18.0 GHz to 26.5 GHz by 0.5 GHz steps
WR28	26.5 GHz to 40.0 GHz by 0.5 GHz steps
WR22	33.0 GHz to 50.0 GHz by 0.5 GHz steps
WR15	50.0 GHz to 75.0 GHz by 1.0 GHz steps
WR10	92.0 GHz to 98.0 GHz by 1.0 GHz steps

The Reports of Calibration and Special Test give, with uncertainties, the magnitude and phase of the reflection coefficient, effective efficiency, and calibration factor of the device under test.

Definitions:

Effective Efficiency _e

The effective efficiency _e is the ratio of the bolometrically substituted dc power for a thermistor detector or the power read from the power meter for a thermocouple detector to the net CW rf microwave power delivered to the power detector.

Bolometrically Substituted dc Power

The bolometrically substituted dc power is the change in dc (or audio frequency) bias power required to maintain the resistance of the thermistor element at a constant value following the application of rf or microwave power.

Calibration Factor, K _B

The calibration factor is the ratio of the bolometrically substituted dc power for a thermistor detector or the power read from the power meter for a thermocouple detector to the CW rf microwave power incident upon the thermistor detector. K _B = _e (1- | | ² ).

Reflection Coefficient Magnitude, | | and Arg ( )

The reflection coefficient magnitude and phase (argument of reflection coefficient) is the ratio of the reflected wave voltage amplitude to the incident wave voltage amplitude and phase.

Typical Effective Efficiency Uncertainties for Coaxial Thermistor and Thermoelectric Detectors
Connector Type	Frequency Range	Thermistor Uncertainties	Thermoelectric Uncertainties
Type-N	0.1 MHz to 10.0 MHz	0.0028-0.005	N/A
Type-N	10 MHz to 18.0 GHz	0.003-0.0073	0.013-0.016
GPC7	10 MHz to 18.0 GHz	0.007-0.016	N/A
3.5 mm	0.05 GHz to 33.0 GHz	0.0067-0.017	0.017-0.022
2.92 mm	0.05 GHz to 40.0 GHz	0.007-0.023	0.018-0.023
2.4 mm	0.05 GHz to 50.0 GHz	0.007-0.028	0.016-0.031

Typical Effective Efficiency Uncertainties for Waveguide Thermistor Detectors
Flange Size	Frequency Range	Uncertainties
WR90	8.2 GHz to 12.4 GHz	0.0108
WR62	12.4 GHz to 18.0 GHz	0.0108
WR42	18.0 GHz to 26.5 GHz	0.0108
WR28	26.5 GHz to 40.0 GHz	0.0108
WR22	33.0 GHz to 50.0 GHz	0.0128
WR15	50.0 GHz to 75.0 GHz	0.017
WR10	92.0 GHz to 98.0 GHz	0.0206

NIST Model CN Reference Standard (61137C-61138C)

This premium service provides he measurements as a function of frequency for a NIST-designed coaxial reference standard with a Type N connector. The reference standard, designated Model CN (Coaxial with a Type N connector), is a bolometric, dc-substitution power detector that must be used with a NIST Type IV power meter (available from several commercial sources). The detector is designed as an optimum transfer standard which can be measured directly in the NIST coaxial microcalorimeter. To use this service, the customer needs to have a CN detector (contact staff for information).

Figure 9.1 compares the expanded uncertainty of the premium service with that of the regular service for coaxial thermistor detectors.

Measurements are made at frequencies over the range from 50 MHz to 18 GHz (Service ID Number 61137C) or customer specified frequencies (Service ID Number 61138C). Figure 9.1 compares the expanded uncertainty of the premium service with that of the regular service for coaxial thermistor detectors.

References-Thermistor Detectors

Direct Comparison Transfer of Microwave Power Sensor Calibration , M. Weidman, Natl. Inst. Stand. Technol. (U.S.), Tech. Note 1379 (January 1996).

A Calibration Service for Reference Standards for Microwave Power, F. Clague, Natl. Inst. Stand. Technol., Tech. Note 1374 (May 1995).

Microcalorimeter for GPC-7 Coaxial Transmission Line , F. Clague, Natl. Inst. Stand. Technol., Tech. Note 1358 (August 1993).

Coaxial Reference Standard for Microwave Power, F. Clague and P. Voris, Natl. Inst. Stand. Technol., Tech. Note 1357 (April 1993).

Measurement Service for High-Power CW Wattmeter at the National Institute of Standards and Technology , J. A. Jargon and G. Rebuldela, Proc. of the Meas. Sci. Conf., Anaheim, CA (Jan. 1993).

Basic RF and Microwave Measurements: A Review of Selected Programs , A. J. Estin, J. R. Juroshek, R. B. Marks, F. R. Clague, and J. Wayde Allen, Metrologia 29, 135-151 (1992).

High Power CW Wattmeter Calibration at NIST, G. Rebuldela and J. A. Jargon, J. Res. Natl. Inst. Stand. Technol., 97 (6), pp. 673-687 (Nov.-Dec. 1992).

WR-10 Millimeter Wave Microcalorimeter , M. Weidman and P. Hudson, Natl. Bur. Stand. (U.S.), Tech. Note 1044 (June 1981).

A Semiautomated Six-Port for Measuring Millimeter-Wave Power and Complex Reflection Coefficient, M. Weidman, IEEE Trans. Micro. Theory Tech. MTT-25, 12 (Dec. 1977).

Performance Characteristics of an Automated Broad-Band Bolometer Unit Calibration System, E. Komarek, IEEE Trans. Micro. Theory Tech. MTT-25, 12 (Dec. 1977).

Theory of UHF and Microwave Measurements Using the Power Equation Concept , G. F. Engen, Natl. Bur. Stand. (U.S.), Tech. Note 637 (Apr. 1973).

Application of an Arbitrary Six-Port Junction to Power Measurement Problems , G. Engen and C. Hoer, IEEE Trans. Instrum. Meas. IM-21, 470 (Nov. 1972).

WR-15 Microwave Calorimeter and Bolometer Unit , M. Harvey, Natl. Bur. Stand. (U.S.), Tech. Note 618 (May 1972).

Accurate Microwave High-Power Measurements Using a Cascaded Coupler Method , K. E. Bramall, J. Res. Natl. Bur. Stand. (U.S.), 75C (3 and 4), 185 (July-Dec. 1971).

Scattering Parameters of Passive One and Two-Port Devices

Technical Contacts:
Ronald A. Ginley
Tel: 303/497-3634
E-mail: rginley@boulder.nist.gov

Puanani L. DeLara
Administration and Logistics
Tel: 303/497-3753
Fax: 303/497-7592
E-mail: calibration@boulder.nist.gov

Do not ship instruments or standards to the mailing address listed below. Contact the technical staff for the shipping address.

Mailing Address:
National Institute of Standards and Technology
M.C. 818.01
325 Broadway
Boulder, CO 80305-3328

Service ID Number	Description of Services	Fee ($)
The following tests are for two-port 50 ohm devices with coaxial connectors.
61200S	Measurement setup charge for all Coaxial Two-port Measurements with GR900, GPC7 or Type-N Connectors, Frequencies of 0.05 GHz and 0.1 GHz-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61201S	Measurement setup charge for all Coaxial Two-port Measurements with GR900, GPC7 or Type-N Connectors, Frequencies at or above 0.2 GHz-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61202S	Measurement setup charge for all Coaxial Two-port Measurements with 3.5 mm, 2.92 mm or 2.4 mm Connectors, Frequencies of 0.05 GHz and 0.1 GHz-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61203S	Measurement setup charge for all Coaxial Two-port Measurements with 3.5 mm, 2.92 mm or 2.4 mm Connectors, frequencies at or above 0.2 GHz-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61211S	Fixed Two-Port Devices with GR900, GPC7 or Type-N Connectors ²	At Cost
61212C	Variable Two-Port Devices with GR900, GPC7 or Type-N Connectors ²	At Cost
61213S	Fixed Two-Port Devices with 3.5 mm, 2.92 mm or 2.4 mm Connectors ²	At Cost
61214S	Variable Two-Port Devices with 3.5 mm, 2.92 mm or 2.4 mm Connectors ²	At Cost
The following tests are for Two-port devices with waveguide flanges
61220S	Measurement setup charge for all Waveguide Two-port Measurements EXCEPT WR15-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61221S	Measurement setup charge for all WR15 Waveguide Two-port Measurements-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61222S	Additional Measurement setup charge for all VARIABLE Waveguide Two-Port Measurements-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61223S	Fixed and Variable Rectangular Waveguide Two-port Devices with WR90 Flanges ²	At Cost
61224S	Fixed and Variable Rectangular Waveguide Two-port Devices with WR62 Flanges ²	At Cost
61225S	Fixed and Variable Rectangular Waveguide Two-port Devices with WR42 Flanges ²	At Cost
61226S	Fixed and Variable Rectangular Waveguide Two-port Devices with WR28 Flanges ²	At Cost
61227S	Fixed and Variable Rectangular Waveguide Two-port Devices with WR22 Flanges ²	At Cost
61228S	Fixed and Variable Rectangular Waveguide Two-port Devices with WR15 Flanges ²	At Cost
61231S	Fixed and Variable Rectangular Waveguide Two-port Devices with WR10 Flanges ²	At Cost
The following tests are for One-port 50 devices with coaxial connectors.
61250S	Measurement setup charge for all Coaxial One-port Measurements with GR900, GPC7 or Type-N Connectors, frequencies of 0.05 GHz and 0.1 GHz-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61251S	Measurement setup charge for all Coaxial One-port Measurements with GR900, GPC7 or Type-N Connectors, frequencies at or above 0.2 GHz-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61252S	Measurement setup charge for all Coaxial one-port Measurements with 3.5 mm, 2.92 mm or 2.4 mm Connectors, frequencies of 0.5 GHz and 0.1 GHz-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61253S	Measurement setup charge for all Coaxial One-port Measurements with 3.5 mm, 2.92 mm or 2.4 mm Connectors, frequencies at or above 0.2 GHz-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61261S	Fixed One-port Devices with GR900, GPC7 or Type N Connectors ²	At Cost
61262S	Variable One-port Devices with GR900, GPC7 or Type N Connectors ²	At Cost
61263S	Fixed One-port Devices with 3.5 mm, 2.92 mm or 2.4 mm Connectors ²	At Cost
61264S	Variable One-port Devices with 3.5 mm, 2.92 mm or 2.4 mm Connectors ²	At Cost
The following tests are for One-port Devices with waveguide flanges.
61270S	Measurement setup Charge for all Waveguide One-port Measurements-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61271S	Additional Measurement setup charge for all VARIABLE Waveguide One-port Measurements-one setup charge for multiple devices with the same connectors and frequencies ¹	At Cost
61272S	Fixed and Variable Rectangular Waveguide One-port Devices with WR90 Flanges ²	At Cost
61273S	Fixed and Variable Rectangular Waveguide One-port Devices with WR62 Flanges ²	At Cost
61274S	Fixed and Variable Rectangular Waveguide One-port Devices with WR42 Flanges ²	At Cost
61275S	Fixed and Variable Rectangular Waveguide One-port Devices with WR28 Flanges ²	At Cost
61276S	Fixed and Variable Rectangular Waveguide One-port Devices with WR22 Flanges ²	At Cost
61277S	Fixed and Variable Rectangular Waveguide One-port Devices with WR15 Flanges²	At Cost
61278S	Fixed and Variable Rectangular Waveguide One-port Devices with WR10 Flanges ²	At Cost
Miscellaneous Tests
61290S	Special Microwave and RF Power Measurement Services, by Prearrangement	At Cost
¹ Only one setup charge is necessary for multiple detectors sent in at the same time with the same connector type and measurment frequencies

Fees are subject to change without notice.

² Measurement Frequencies:

Connector Type Waveguide Flange Measured	Typical Frequencies for One and Two-port Measurements (if additional frequencies not covered in this list are required, there may be an additional charge-call for information)
GR900	10.0 MHz to 100 MHz by 10.0 MHz steps
	100.0 MHz to 1 GHz by 50.0 MHz steps
	1.0 GHz to 8.5 GHz by 0.5 GHz steps
Type-N	0.1 MHz to 1.0 MHz by 0.1 MHz steps (for one-ports only)
	1.0 MHz to 10.0 MHz by 1.0 MHz steps (for one-ports only)
	10.0 MHz to 100.0 MHz by 10.0 MHz steps
	100.0 MHz to 18 GHz by 0.2 GHz steps
	1.0 GHz to 18 GHz by 0.2 GHz steps (preferred)
	Older Type-N Frequencies are still supported but not preferred
	1.0 GHz to 2.0 GHz by 0.05 GHz steps
	2.0 GHz to 4.0 GHz by 0.1 GHz steps
	4.0 GHz to 12.4 GHz by 0.2 GHz steps
	12.5 GHz to 18.0 GHz by 0.25 GHz steps
GPC7	10.0 MHz to 100.0 MHz by 10.0 MHz steps
	100.0 MHz to 1.0 GHz by 50.0 MHz steps
	1.0 GHz to 18 GHz by 0.2 GHz steps (preferred)
	2.0 GHz to 4.0 GHz by 0.1 GHz steps
	4.0 GHz to 12.4 GHz by 0.2 GHz steps
	12.5 GHz to 18.0 GHz by 0.25 GHz steps
3.5 mm	0.05 GHz, 0.1 GHz, 0.2 GHz to 33.0 GHz by 0.2 GHz steps and 26.5 GHz
2.92 mm	0.05 GHz, 0.1 GHz and 0.2 GHz to 40 GHz by 0.2 GHz steps
2.4 mm	0.05 GHz, 0.1 GHz and 0.2 GHz to 50 GHz by 0.2 GHz steps
WR90	8.2 GHz to 12.4 GHz by 0.2 GHz steps
WR62	12.4 GHz and 12.5 GHz to 18.0 GHz by 0.25 GHz steps
WR42	18.0 GHz to 26.5 GHz by 0.5 GHz steps
WR28	26.5 GHz to 40.0 GHz by 0.5 GHz steps
WR22	33.0 GHz to 50.0 GHz by 0.5 GHz steps
WR15	50.0 GHz to 75.0 GHz by 1.0 GHz steps
WR10	75.0 GHz to 110.0 GHz by 1.0 GHz steps

General Information

Microwave devices are characterized by their reflection and transmission properties. One-port devices such as matched terminations and offset shorts are characterized by measuring their reflection properties or voltage reflection coefficient. Two-port devices such as attenuators are characterized by measuring both their reflection and transmission properties.

Figure 9.2 shows the reflected and transmitted voltage waves for a typical two-port device. The voltage waves incident to the device are defined as a ₁ and a ₂. The voltage waves reflected from the device are defined as b ₁ and b ₂.

reflected and transmitted voltage waves for a typical two-port device diagram

Figure 9.2 Reflected and Transmitted Voltage Waves for a Typical Two Port Device.

The scattering parameters specify the relationship between the incident and reflected waves. In the case of the two-port in Figure 9.2, the scattering matrix is,

[b ₁] = [S ₁₁ S ₁₂] [a ₁]
[b ₂] = [S ₁₂ S ₂₂] [a ₂]

The scattering matrices shown are complex quantities conveying information on both the magnitude and phase of the quantities of interest.

The attenuation of a two-port device is defined as S ₁₂ and S ₂₁. Most passive microwave devices are reciprocal where S ₁₂ = S ₂₁. The magnitude of the attenuation for a reciprocal device is commonly expressed in dB as

A = -20 log₁₀ ( | S ₁₂ | ), dB

= -20 log₁₀ ( | S ₂₁ | ), dB

Similar definitions exist for single port devices such as terminations and offset shorts. A one port device can be thought of as the special case of a two port device where S ₁₂ = S ₂₁ = 0. The voltage reflection coefficient for a one port device is commonly given as

= b/a,

where a is the voltage wave incident on the device, and b is the voltage wave reflected from the device.

All scattering parameters are referenced to some idealized transmission line. At NIST, all coaxial measurements are referenced to an idealized, air dielectric, 50 transmission line of specified dimensions. Similarly, all waveguide measurements are referenced to an idealized, air dielectric, precision waveguide section of specified dimensions. Details of the reference standard are available on request.

Devices submitted for measurement should be in good repair and require only very minor cleaning of connector surfaces. NIST does not provide repair services. Items received requiring maintenance will be returned to the customer, and a handling fee will be charged.

Fixed and Variable Attenuators

Coaxial fixed and variable attenuators are measured on either a NIST Dual Six-Port Vector Network Analyzer (VNA) or on a commercial VNA.

Coaxial attenuators are measured relative to a reference characteristic impedance of 50 . For fixed attenuators, the complete set of two-port, complex s-parameters are measured. The measurement report gives the magnitude and phase of S ₁₁, S ₂₂ and S ₁₂ = S ₂₁ .

For variable attenuators, normally only the change in attenuation from the zero setting is of interest. The test report for variable attenuators show the change in the magnitude of S ₁₂ from the zero setting versus frequency for selected attenuator settings. Complete scattering parameter measurements for variable attenuators are available by special request.

Fixed and Variable One-port Devices

Waveguide one-port devices must be fitted with standard waveguide flange connectors. The faces of these flanges should be machined flat and smooth and should not contain protrusions or indentations. Considerable care must be exercised in keeping the mating connector flange surfaces smooth and clean. Accurate alignment of the waveguide joint and flanges is also very important. The back of the flange which makes contact with the connecting bolts should be nominally flat and free of soft materials, including paint. The connecting holes of the flange should be symmetrically and accurately aligned to the rectangular waveguide opening.

Typical Uncertainties for Coaxial Reflection Coefficient (S₁₁ and S₂₂) Measurements

Connector Type	Frequency Range	Magnitude Uncertainties	Phase Uncertainties (deg.)
GR900	0.01 GHz to 8.5 GHz	0.0035-0.0045	0.05-180
GPC7	0.01 GHz to 18.0 GHz	0.0070-0.0085	3.80-180
Type-N	0.01 GHz to 18.0 GHz	0.0035-0.0075	1.90-180
3.5 mm	0.05 GHz to 33.0 GHz	0.0070-0.0135	3.80-180
2.92 mm	0.05 GHz to 40.0 GHz	0.0095-0.0195	2.30-180
2.4 mm	0.05 GHz to 50.0 GHz	0.0125-0.0210	2.80-180

Typical Uncertainties for Coaxial Transmission Coefficient (S₁₂ and S₂₁) Measurements

Connector Type	Frequency Range	Attenuation Level (dB)	Magnitude Uncertainties (dB)	Phase Uncertainties (deg)
GR900	0.01 GHz to 8.5 GHz	0 - 40	0.01-0.041	0.07-0.89
		40 - 55	0.040-0.071
		55 - 70	0.070-0.300
GPC7	0.0 1 GHz to 18.0 GHz	0 - 40	0.009-0.047	0.12-3.57
		40 - 55	0.040-0.075
		55 - 70	0.070-0.310
Type-N	0.0 1 GHz to 18.0 GHz	0 - 40	0.014-0.042	0.16-1.92
		40 - 55	0.040-0.071
		55 - 70	0.070-0.310
3.5 mm	0.0 5 GHz to 33.0 GHz	0 - 40	0.011-0.52	0.21-3.27
		40 - 55	0.040-0.078
		55 - 70	0.071-0.312
2.92 mm	0.0 5 GHz to 40.0 GHz	0 - 40	0.011-0.059	0.21-3.95
		40 - 55	0.040-0.083
		55 - 70	0.071-0.313
2.4 mm	0.0 5 GHz to 50.0 GHz	0 - 40	0.021-0.084	0.21-4.92
		40 - 55	0.060-0.108
		55 - 70	0.091-0.335

Typical Uncertainties for Waveguide Reflection Coefficient (S₁₁ and S₂₂) Measurements

Flange Size	Frequency Range	Magnitude Uncertainties	Phase Uncertainties (deg.)
WR90	8.2 GHz to 12.4 GHz	0.0046-0.0075	1.98-180
WR62	12.4 GHz to 18.0 GHz	0.0046-0.0075	2.40-180
WR42	18 GHz to 26.5 GHz	0.0038-0.0055	1.64-180
WR28	26.5 GHz to 40.0 GHz	0.0038-0.0055	1.75-180
WR22	33.0 GHz to 50.0 GHz	0.0076-0.0110	3.17-180
WR15	50.0 GHz to 75.0 GHz	0.0076-0.0110	3.73-180
WR10	75.0 GHz to 110 GHz	0.0140-0.0244	4.20-180

Typical Uncertainties for Waveguide Transmission Coefficient (S₁₂ and S₂₁) Measurements

Flange Size	Frequency Range	Attenuation Level (dB)	Magnitude Uncertainties (dB)	Phase Uncertainties (deg.)
WR90	8.2 GHz to 12.4 GHz	0 - 40	0.031-0.046	0.38
		40 - 50	0.046-0.072
		50 - 70	0.072-0.310
WR62	12.4 GHz to 18.0 GHz	0 - 40	0.031-0.046	0.65
		40 - 50	0.046-0.072
		50 - 70	0.072-0.310
WR42	18 GHz to 26.5 GHz	0 - 40	0.023-0.042	1.03
		40 - 50	0.042-0.070
		50 - 70	0.070-0.310
WR28	26.5 GHz to 40.0 GHz	0 - 40	0.023-0.042	1.19
		40 - 50	0.042-0.070
		50 - 70	0.070-0.310
WR22	33.0 GHz to 50.0 GHz	0 - 40	0.023-0.042	1.79
		40 - 50	0.042-0.070
		50 - 70	0.070-0.310
WR15	50.0 GHz to 75.0 GHz	0 - 40	0.042-0.081	2.71
		40 - 50	0.081-0.138
		50 - 70	0.138-0.620
WR10	75.0 GHz to 110.0 GHz	0 - 40	0.047-0.084	3.93
		40 - 50	0.084-0.140
		50 - 70	0.140-0.621

References-CS-Parameters of Passive 1-Port and 2-Port Devices

Measurements of the Characteristic Impedance of Coaxial Air Line Standards , J. R. Juroshek and G. M. Free, IEEE Trans. on MTT, 42 (2), 186-191 (Feb. 1994).

Basic RF and Microwave Measurements: A Review of Selected Programs , A. J. Estin, J. R. Juroshek, R. B. Marks, F.R. Clague, and J. Wayde Allen, Metrologia 29, 135-151 (1992).

"Thru-Reflect-Line": An Improved Technique for Calibrating the dual Six-Port Automatic Network Analyzer , G. F. Engen and C. A. Hoer, IEEE Trans. Micr. Theory Tech. MTT-27, 987 (Dec. 1979).

A Network Analyzer Incorporating Two Six-Port Reflectometers , C. A. Hoer, IEEE Trans. Micr. Tech. MTT-25, 1070 (Dec. 1977).

The Six-Port Reflectometer: An Alternative Network Analyzer , G. F. Engen, IEEE Trans. Micr. Theory Tech. MTT-25, 1075 (Dec. 1977).

Application of Waveguide and Circuit Theory to the Development of Accurate Microwave Measurement Methods and Standards , R. W. Beatty, Natl. Bur. Stand. (U.S.), Monogr. 137 (Aug. 1973).

Specifications and Test Methods for Fixed and Variable Attenuators, dc to 40 GHz, IEEE Standard 474 (1973).

Basic Theory of Waveguide Junctions and Introductory Microwave network Analysis, D. M. Kearns and R. W. Beatty, Intl. Ser. of Monogr. in Electromag. Waves 13, 59, Pergammon Press, New York, NY (1967).

Electrical Parameters of Precision, Coaxial, Air Dielectric Transmission Lines , R. E. Nelson and M. R. Coryell, Natl. Bur. Stand. (U.S.), Monogr. 96 (June 1966).

High Accuracy Attenuation Measurements

Technical Contacts:
Ronald A. Ginley
Tel: 303/497-3634
E-mail: rginley@boulder.nist.gov

Jeff A. Jargon
Tel: 303/497-3596
E-mail: jargon@boulder.nist.gov

Puanani L. DeLara
Administration and Logistics
Tel: 303/497-3753
Fax: 303/497-7592
E-mail: calibration@boulder.nist.gov

Do not ship instruments or standards to the mailing address listed below. Contact the technical staff for the shipping address.

Mailing Address:
National Institute of Standards and Technology
M.C. 818.01
325 Broadway
Boulder, CO 80305-3328

Service ID Number	Description of Services	Fee ($)
61330S	Attenuation Measurements of Three-Port and Two-Port Devices at 1.25 MHz, 0 dB and 6 dB	At Cost

Fees are subject to change without notice.

Attenuation Measurements at 1.25 MHz (61330S)

An additional measurement service is available for attenuation measurements of special three-port devices at 1.25 MHz. A measurement system has been developed to measure the change in the ratio S ₂₁/S ₃₁ of special stable two-position, three-port devices sometimes called voltage doublers, at 1.25 MHz. The device must have an input for a 1.25 MHz source (port 1), a reference output (port 3), and an output (port 2) with a level switchable to two different values. The two levels of the bi-level output have a nominal ratio of 6.0206 dB.

If P _r1 is the reference power level when the bi-level output is at level 1 (P _b1), and P _r2 is the reference power level when the bi-level output is at level 2 (P _b2), then the parameter measured is given by the following equation:
10log subscript10(P subscript b1 /P subscript r1 -10 log subscript 10(P subscript b2 /P subscript r2)
where the subscripts (1) and (2) refer to the switch positions 1 and 2, respectively. The above is equivalent to
10 log subscript 10 |(S subscript 21 (1) /S subscript 31(1))/(S subscript 21 (2)/S subscript 31 (2))| superscript 2.
The loads presented to the two outputs are 50 . The device must allow the signal input to be of such strength that the bi-level output is at least 10 mW in the high-level position.

The Type A standard uncertainty of the measurement system in measuring a 6 dB change in attenuation is 8.2 µB. Typical Type B standard uncertainties are on the order of 0.3 µB to 0.5 µB (1 µB = 10^-5 dB). Two-port step attenuators having a nominal change in attenuation of 6 dB can also be measured by this system at 1.25 MHz.

References-High Accuracy Attenuation Measurements

Basic RF and Microwave Measurements: A Review of Selected Programs , A. J. Estin, J. R. Juroshek, R. B. Marks, F. R. Clague, and J. Wayde Allen, Metrologia 29, 135-151 (1992).

A Calibration Service for 30 MHz Attenuation and Phase Shift , R.T. Adair and D. H Russell, Natl. Bur. Stand. (U.S.), SP 250-32 (1988).

1.25 MHz Attenuation Measurement System , R. A. Ginley and C. M. Allred, IEEE Trans. Instrum. Meas., IM-35 (4), Pt. 1 (Dec. 1986).

Specifications and Test Methods for Fixed and Variable Attenuators, dc to 40 GHz, IEEE Standard 474 (1973).

6 back to top of page | back to index of electromagnetic measurements

Thermal Noise Measurements

Technical Contacts:
David K. Walker
Tel: 303/497-5490
email: dwalker@boulder.nist.gov

James P. Randa
Tel: 303/497-3150
email: randa@boulder.nist.gov

Puanani L. DeLara
Administration and Logistics
Tel: 303/497-3753
Fax: 303/497-7592
E-mail: calibration@boulder.nist.gov

Do not ship instruments or standards to the mailing address listed below. Contact the technical staff for the shipping address.

Mailing Address:
National Institute of Standards and Technology
M.C. 818.01
325 Broadway
Boulder, CO 80305-3328

Service ID Number	Frequency	Connector Type	Device Requirements/Service	Fee ($)
61410S	30 MHz 60 MHz	Coaxial N Precision (PIN) GPC 3.5 (PIN) GPC 7 14 mm	Temperature < 15 000 K (ENR < 17 dB) VSWR < 1.2
	Set Up Charge, per order			4180
	Per Frequency			6875
61420S	1.0 GHz to 12.4 GHz Continuous Frequencies	Coaxial 14 mm (1 GHz to 4 GHz) GPC 7 N Precision (PIN) GPC 3.5 (PIN) GPC 2.4 (PIN) (8 GHz to 12.4 GHz)	Temperature < 15 000 K (ENR < 17 dB) Reflection Coefficient < 0.2
	Set Up Charge, per order			5767
	Per Frequency			703
61425S	12.4 GHz to 18.0 GHz Continuous Frequencies	Coaxial GPC 7 N Precision (PIN) GPC 3.5 (PIN) GPC 2.4 (PIN)	Temperature < 15 000 K (ENR < 17 dB) Reflection Coefficient < 0.2
	Set Up Charge, per order			7845
	Per Frequency			4521
61430S	18.0 GHz to 26.0 GHz Continuous Frequencies	Coaxial GPC 3.5 (PIN) GPC 2.4 (PIN)	Temperature < 15 000 K (ENR < 17 dB) Reflection Coefficient < 0.2
	Set Up Charge, per order			7661
	Per Frequency			4369
61435S	26.5 GHz to 40 GHz Continuous Frequencies	Coaxial GPC 2.4 (PIN)	Temperature < 15 000 K (ENR < 17 dB) Reflection Coefficient < 0.2
	Set Up Charge, per order			10897
	Per Frequency			6353
61450S	8.2 GHz to 12.4 GHz Continuous Frequencies	Waveguide WR90	Temperature < 15 000 K (ENR < 17 dB) Reflection Coefficient < 0.2
	Set Up Charge, per order			5951
	Per Frequency			703
61455S	12.4 GHz to 18.0 GHz Continuous Frequencies	Waveguide WR62	Temperature < 15 000 K (ENR < 17 dB) Reflection Coefficient < 0.2
	Set Up Charge, per order			7661
	Per Frequency			4278
61460S	18.0 GHz to 26.0 GHz Continuous Frequencies	Waveguide WR42	Temperature < 15 000 K (ENR < 17 dB) Reflection Coefficient < 0.2
	Set Up Charge, per order			7661
	Per Frequency			4278
61465S	26.5 GHz to 40.0 GHz Continuous Frequencies	Waveguide WR28	Temperature < 15 000 K (ENR < 17 dB) Reflection Coefficient < 0.2
	Set Up Charge, per order			9951
	Per Frequency			4887
61470S	33 GHz to 50 GHz Continuous Frequencies	Waveguide WR22	Temperature < 15 000 K (ENR < 17 dB) Reflection Coefficient < 0.2
	Set Up Charge, per order			10591
	Per Frequency			5986
61475S	50 GHz to 65 GHz Continuous Frequencies	Waveguide WR15	Temperature < 15 000 K (ENR < 17 dB) Reflection Coefficient < 0.2
	Set Up Charge, per order			10591
	Per Frequency			7821
61495S	Special Noise Temperature Measurements, by Prearrangement			At Cost

Fees are subject to change without notice.

Noise Temperature Measurements (61410S-61465S)

Noise temperature measurements are available on single-port, coaxial and rectangular-waveguide noise sources under conditions of continuous, unmodulated operation. Precision coaxial connectors or clean, smooth, and flat standard EIA waveguide flanges are required. Measurement results on devices submitted with adapters attached may apply only to the source/ adapter combination. Complete operating instructions and special electronic connectors should be supplied, and pertinent operating conditions (voltages, circuits, etc.) should be specified for the noise source to be measured. Devices submitted that are not of sufficient quality or not mechanically compatible with the measuring system will be rejected, and an appropriate fee will be charged. Availability of measurements at specific frequencies and for various connector types is specified above.

The measurement uncertainty varies with noise temperature, reflection coefficient, connector type, and source stability. The relative expanded uncertainty typically lies between 0.9 % and 1.5 % of the noise temperature.

The noise temperature measured and reported is the available noise temperature, defined to be the available noise power per unit bandwidth divided by Boltzmann's constant. For noise temperatures above T ₀= 290K, we also report the excess noise ratio delivered into a reflectionless load (ENR₀). It is defined by

where is the available noise temperature, and is the reflection coefficient of the device under test. If the available ENR is desired, it can be computed directly from the available noise temperature by

For most devices, the difference between ENR ₀ and ENR _av is very small.

NIST noise-temperature measurements are performed on total-power radiometers, using two primary thermal noise standards, one of which is at ambient temperature and one of which is at cryogenic (liquid nitrogen) temperature. For measurements at 30 and 60 MHz, tunable coaxial standards [1] are used. From 1 to 12.4 GHz, coaxial standards [2] are used, and for 12.4 GHz and above, waveguide/horn standards [3,4] are used. The radiometers themselves are described in references [1,5-7]. The NIST radiometers are double-sideband, total-power radiometers. The IF frequency is 0 (i.e., the LO frequency is set to the measurement frequency), and the IF bandwidth B_IF ranges from 5 MHz to 20 MHz, depending on the particular radiometer. Thus the reported noise temperature represents an average over a frequency range of 2B_IF centered at the measurement frequency.

At least three independent measurements (including separate system calibrations, where applicable) of the noise temperature are made at each frequency. The noise source is allowed to warm up before any measurements are made. For many connector types and frequencies, the measurements are made through adapters. The procedure for characterizing the adapter and removing its effect is described in references [8,9].

The combined standard uncertainty is composed of type-A and type-B uncertainties [10,11]. Type-A uncertainties (u _A) are those that are measured and determined by statistical methods, such as the standard deviation of the means of several independent measurements of the quantity of interest. Type-B uncertainties (u _B) are those determined by other means, such as estimates of systematic uncertainties. The uncertainty reported is the expanded uncertainty, given by

This corresponds approximately to a 95 % confidence level. Details of the uncertainty analysis can be found in references [5-7,12].

Special Noise Temperature Measurements (61495S)

Measurements of electromagnetic thermal noise other than those listed above can sometimes be arranged on a case-by-case basis. These may include measurements through adapters, measurements out of the parameter ranges specified above, and measurements on systems currently under development. Such measurements should be discussed with one of the technical contacts before submitting a device for calibration.

References-Noise Temperature Measurements

[1] NBS 30/60 Megahertz Noise Measurement System Operation and Service Manual , G. J. Counas and T. H. Bremer, NBSIR 81-1656 (Dec. 1981).

[2] A Coaxial Noise Standard for the 1 GHz to 12.4 GHz Frequency Range , W. C. Daywitt, NBS Tech. Note 1074 (Mar. 1984).

[3] Design and Error Analysis for the WR10 Thermal Noise Standard, W. C. Daywitt, NBS Tech. Note 1071 (Dec. 1993).

[4] The noise temperature of an arbitrarily shaped microwave cavity with application to a set of millimetre wave primary standards, Metrologia, 30 (5) 471-478 (Oct./Nov. 1993).

[5] The 30/60 MHz Tuned Radiometer-The NIST System for Noise Temperature Measurements, C. A. Grosvenor and R. L. Billinger, NIST Tech. Note 1525 (Mar. 2002).

[6] Design and Testing of NFRad-A New Noise Measurement System , C. A. Grosvenor, J. Randa, and R. L. Billinger, NIST Tech. Note 1518 (Mar. 2000).

[7] Noise-Temperature Measurement System for the WR-28 Band , J. Randa and L. A. Terrell, NIST Tech. Note 1395 (Aug. 1997).

[8] Determining adapter efficiency by envelope averaging swept frequency reflection data, W. C. Daywitt, IEEE Trans. on Microwave Theory and Techniques, MTT-38 (11) 1748-1752 (Nov. 1990).

[9] Single-port technique for adaptor efficiency evaluation , S. P. Pucic and W. C. Daywitt, 45th ARFTG Conference Digest, 113-118, Orlando, FL (May 1995).

[10] Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results , B. N. Taylor and C. E. Kuyatt, NIST Tech. Note 1297 (Sept. 1994).

[11] ISO Guide to the Expression of Uncertainty in Measurement, Intl. Org. for Standardization; Geneva, Switzerland (1993).

[12] Uncertainties in NIST Noise-Temperature Measurements , J. Randa, NIST Tech. Note 1502 (Mar. 1998).

Dielectric and Magnetic Material Measurements

Technical Contact:
James R. Baker-Jarvis
Tel: 303/497-5305
E-mail: jjarvis@boulder.nist.gov

Puanani L. DeLara
Administration and Logistics
Tel: 303/497-3753
Fax: 303/497-7592
E-mail: calibration@boulder.nist.gov

Do not ship instruments or standards to the mailing address listed below. Contact the technical staff for the shipping address.

Mailing Address:
National Institute of Standards and Technology
M.C. 818.01
325 Broadway
Boulder, CO 80305-3328

Service ID Number	Description of Services	Fee ($)
61620S	Special Tests for Dielectric and Magnetic Materials 1 kHz to 60 GHz	At Cost
61640S	Special Consulting and Advisory Services for Dielectric and Magnetic Materials, by Prearrangement	At Cost

Fees are subject to change without notice.

Special Tests for Dielectric and Magnetic Materials (61620S)

A special-test measurement service is available for measuring the complex permittivity, * and permeability, µ* of dielectric and magnetic materials, as well as the surface resistance of conductors, at selected RF/microwave frequencies in the spectral range 1 kHz to 60 GHz. The service is capable of characterizing fluids, powders, or bulk solids at room temperatures (23 °C) and, in some cases, over a temperature range of approximately -80 °C to 150 °C. Customers interested in high frequency material characterization measurements should contact NIST staff to discuss their specific needs. The optimal measurement technique used is selected from a number of measurement techniques developed at NIST. The selection depends on a number of factors including whether the material is in fluid, powder or solid form, the volume of material available, its shape factor (for solids), its anticipated loss factor, whether the material is anisotropic, and the desired measurement frequencies and ambient temperature. The resulting measurement uncertainties depend on the technique selected as well as the nominal permittivity of the material under test.

Upon request, NIST staff will prepare a detailed cost quotation that includes estimates of the measurement uncertainties. For the case of solids, each measurement method requires accurately machined test samples with optical-standard tolerances for dimensions, flatness and parallelism. NIST can either perform the machining of test samples, the cost of which is included in the price quotation, or furnish drawings of sample specifications for the customer to perform the necessary machining.

The measurement techniques available at NIST can be divided into three categories: a) cavity resonator methods for low-loss materials (tan < 0.01), b) broadband transmission line methods for medium to high-loss materials, and c) low-frequency impedance measuring methods. Most cavity resonators operate at frequencies above 100 MHz and usually provide single-frequency data, unless the resonators are tunable or can be operated on higher-order modes. Data are usually provided in tabular form. In general, better measurement uncertainties are achievable using cavities and are about 0.5% for '.

Broadband transmission line techniques include coaxial air lines and waveguides of various dimensions, as well as 1- and 2-port open-ended coaxial probe methods. Measured broad-band data are normally provided as linear or logarithmic plots of ', and µ', µ" as a function of frequency with uncertainties included; relative uncertainties of 5% to 10% are typical. The low-frequency impedance measuring methods typically cover the frequency range 1 kHz to 10 MHz and involve measuring capacitance changes for dielectric materials and inductance changes for magnetic materials.

References-Dielectric and Magnetic Material Measurements

Complex Permeability of Demagnetized Microwave Ferrites Near and Above Gyromagnetic Resonance, J. Krupka et al, IEEE Trans. Mag. 32 (3) pp. 1924-1933 (May 1996).

Dielectric and Magnetic Measurements from -50 °C to 200 °C and in the Frequency Band 50 MHz to 2 GHz, J. Baker-Jarvis et al, NIST Internal Report 5045 (Mar. 1996).

Dielectric Measurements of Printed-Wiring and Circuit Boards, Thin Films, and Substrates: An Overview , J. Baker-Jarvis and C. A. Jones, Mat. Res. Soc. Symp. Proc. 381, pp. 153-164 (April 1995).

Analysis of an Open-Ended Coaxial Probe with Lift-Off for Nondestructive Testing, J. Baker-Jarvis et al, IEEE Trans I&M, 43 (5) pp 711-718 (Oct. 1994).

Transmission/Reflection and Short-Circuit Line Methods for Measuring Permittivity and Permeability, J. Baker-Jarvis et al, NIST Tech. Note 1355-R (Dec. 1993).

The NIST 60-mm Diameter Cylindrical Cavity Resonator: Performance Evaluation for Permittivity Measurements , E. J. Vanzura et al, NIST Tech. Note 1354 (Aug. 1993).

NIST Measurement Service for Electromagnetic Characterization of Materials , J. H. Grosvenor, NISTIR 5006 (Aug. 1993).

Shielded Open-Circuited Sample Holders for Dielectric and Magnetic Measurements of Liquids and Powders , J. Baker-Jarvis et al, NISTIR 5001 (Mar. 1993).

Date created: 06/30/1999
Last updated: 01/15/2009