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UL 3 1969

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Radio-Frequency Measurements

in the NBS Institute for Basic

Standards

MAR 6 1973 373

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U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards was established by an act of Congress March 3. 1901. Today,

in addition to serving as the Nation's central measurement laboratory, the Bureau is a principal

focal point in the Federal Government for assuring maximum application of the physical and

engineering sciences to the advancement of technology in industry and commerce. To this end

the Bureau conducts research and provides central national services in four broad program

areas. These are: (1) basic measurements and standards. (2) materials measurements and

standards, (3) technological measurements and standards, and (4) transfer of technology.

The Bureau comprises the Institute for Basic Standards, the Institute for Materials Research, the

Institute for Applied Technology, the Center for Radiation Research, the Center for Computer

Sciences and Technology, and the Office for Information Programs.

THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United

States of a complete and consistent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essential services leading to accurate and

uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of an Office of Measurement Services and the following technical

divisions:Applied Mathematics—Electricity—Metrology—Mechanics—Heat—Atomic and Molecular Physics—Radio Physics -—Radio Engineering -—Time and Frequency -—Astrophysics - —Cryogenics.

-

THE INSTITUTE FOR MATERIALS RESEARCH conducts materials research leading to im- proved methods of measurement standards, and data on the properties of well-characterized

materials needed by industry, commerce, educational institutions, and Government; develops,

produces, and distributes standard reference materials; relates the physical and chemical properties of materials to their behavior and their interaction with their environments; and provides

advisory and research services to other Government agencies. The Institute consists of an Office of Standard Reference Materials and the following divisions: Analytical Chemistry—Polymers—Metallurgy—Inorganic Materials—Physical Chemistry.

THE INSTITUTE FOR APPLIED TECHNOLOGY provides technical services to promote

the use of available technology and to facilitate technological innovation in industry and Government; cooperates with public and private organizations in the development of technological

standards, and test methodologies; and provides advisory and research sen ices for Federal, state, and local government agencies. The Institute consists of the following technical divisions and

offices: Engineering Standards—Weights and Measures — Invention and Innovation — Vehicle Systems Research—Product Evaluation—Building Research—Instrument Shops—-Meas- urement Engineering—Electronic Technology—Technical Analysis.

THE CENTER FOR RADIATION RESEARCH engages in research, measurement, and application of radiation to the solution of Bureau mission problems and the problems of other agencies and institutions. The Center consists of the following divisions: Reactor Radiation—Linac Radiation—Nuclear Radiation—Applied Radiation. THE CENTER FOR COMPUTER SCIENCES AND TECHNOLOGY conducts research and

provides technical services designed to aid Government agencies in the selection, acquisition, and effective use of automatic data processing equipment; and serves as the principal focus

for the development of Federal standards for automatic data processing equipment, techniques,

and computer languages. The Center consists of the following offices and divisions: Information Processing Standards—Computer Information — Computer Services — Sys- tems Development—Information Processing Technology.

THE OFFICE FOR INFORMATION PROGRAMS promotes optimum dissemination and

accessibility of scientific information generated within NBS and other agencies of the Federal government: promotes the development of the National Standard Reference Data System and a system of information analysis centers dealing with the broader aspects of the National Measure- ment System, and provides appropriate services to ensure that the NBS staff has optimum accessibility to the scientific information of the world. The Office consists of the following

organizational units:

Office of Standard Reference Data—Clearinghouse for Federal Scientific and Technical

Information —Office of Technical Information and Publications—Library—Office of Public Information—Office of International Relations.

! Headquarters and Laboratories at Gaithersburg. Maryland, unless otherwise noted: mailing address Washingto

a Located at Boulder. Colorado S0302.

"' Located at 5285 Port Royal Road. Springfield. Virginia 22151.
UNITED STATES DEPARTMENT OF COMMERCE

Maurice H. Stans, Secretary

NATIONAL BUREAU OF STANDARDS • A. V. Astin, Director

NBS TECHNICAL NOTE 373

ISSUED JUNE 1969

Nat. Bur. Stand. (U.S.), Tech. Note 373, 116 pages (June 1969)

CODEN: NBTNA

RADIO- FREQUENCY MEASUREMENTS IN THE

NBS INSTITUTE FOR BASIC STANDARDS

EDITED BY ROBERTS. POWERS

AND WILBERT F. SNYDER

Institute for Basic Standards

National Bureau of Standards

Boulder, Colorado 80302

NBS Technical Notes are designed to supplement the Bureau's regular publications program. They provide a means tor making available scientific data that are of transient or limited interest. Technical Notes may be

listed or referred to in the open iiterature.

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C., 20402

Price $1.00

TABLE OF CONTENTS

Abstract . . .

• iv

Introduction . . . . „ 1 Measurement Representation . . . „ . 5

Time and Frequency Standards . . . . . 6

Time and Frequency Dissemination . . 7, 8, 9, 10

Cavity Wavemeters . 11

Stability of Stable Oscillators and Other Signal Sources ...... 12

RF Power in Coaxial Systems: . . . 13, 14

Dry Load Calorimetric Measurement and Coaxial

Bolometer Units „ „ . 13

Flow Calorimetric Measurement . 14

Microwave Power: „ 15, 16, 17

Coaxial Bolometer Units, Adapter Method „ 15

Waveguide Bolometer Units: 16, 17

Microcalorimetric Measurement ............. 16

Impedance Measurement 17

RF Peak-Pulse Power in Coaxial Systems <> 18

Noise Temperature: . 19, 20

Noise Temperature, Coaxial Systems ............... 19

Effective Noise Temperature, Waveguide Systems .... Z0

PvF Voltage, Coaxial Systems ............................. 21

RF Microvoltage ........... 22

Pulse Voltage . . 23

Field Strength 24

Field Strength Meters, Antennas . . . . 25

Attenuation: 26, 27

Coaxial Systems 26

Waveguide Systems 27

Phase Shift: 28,29

Coaxial Phase Shifters 28

Waveguide Phase Shifters 29

Reflection Coefficient Magnitude of Waveguide Devices „ . 30

Distributed Parameters in Coaxial Systems 31

High Frequency Immittance 32

Large Complex Relative Dielectric Permittivity 33

High Frequency Relative Dielectric Permittivity 34

High Frequency Dielectric Loss „ 35

Microwave Complex Relative Dielectric Permittivity: ...... 36, 37

Dielectric Loaded Transmission Lines .............. 36

Transmission Cavities 37

in
ABSTRACT

This volume is a collection, of diagrams, tables, and text

material, which has been assembled to show the interrelationships between various radio frequency measurements

made by the Institute for Basic Standards (IBS). In particular,

the measurements are those which lead to services provided

to the public or to other government agencies. These services

include not only calibrations made for fees, but the broadcast

services of the four NBS radio stations. Measurements made

as part of the IBS research and development program are not

included.

The information included is designed to give the users

and potential users of the radio frequency services a clearer

understanding of the origins of the measurement output of IBS

in this field.

Keywords: accuracy; calibration services; measurements;

measurement techniques; radio frequency;

uncertainties of measurement.

IV
RADIO -FREQUENCY MEASUREMENTS IN THE

NBS INSTITUTE FOR BASIC STANDARDS

Edited by Robert S. Powers

and Wilbert F. Snyder

INTRODUCTION

This volume is being published to give users of the National

Bureau of Standards calibration services at radio frequencies a collection of information about the uncertainties given in Report of

Calibration. It is a collection of diagrams, tables, and text material

which shows the interrelationships among various radio frequency

measurements made by the Institute for Basic Standards (IBS). In

particular, the measurements are those which lead to services provided to the public or to other government agencies. These services

include not only calibrations made for fees, but also the broadcast

services of the four NBS radio stations. Measurements made as part

of the IBS research and development program are not included.

It is hoped that this information will give the users and potential

users of the radio-frequency services a clearer understanding of the

origins of the measurement output of IBS in this field.

Generally, the sequence of measurements which leads to an output

calibration or other service is shown by measurement flow charts.

The notations of these charts are explained on page 5.

Each measurement may have errors arising from many sources.

Typical values of these errors are given in one of two ways. In most

cases, known or suspected sources of bias error are listed along with

typical values of the random errors (or imprecision) . In addition, in

many instances, Error Flow Diagrams have been included to show

more explicitly the way the various sources of uncertainty enter the

measurement chain.

The study that led to these charts and tables was initiated to provide the management of the Institute and its divisions with a fairly

detailed analysis of how the elements of the NBS part of the national

system of radio measurements relate to each other. This was to help

identify those parts of the "NBS subsystem of radio measurement"

which could make the greatest contributions to improving the output of
the subsystem as a whole, if given the limited funds that are available.

The principal suggestion arising from the study was that significant

gains in the overall performance of the IBS system could result from

improvement in the treatment and reporting of the known error sources.

At this time, a program to improve the reporting of uncertainties is

under way.

This information is current as of approximately January, 1969.

It serves to update, and present in a different form, some of the

information in NBS Technical Note 262. *

The term "error" means the difference between the value actually

measured and some "true value" which would have been obtained from a hypothetical "perfect" experiment.** The term "uncertainty" refers to

the range within which the metrologist believes the actual error, as defined above, does fall. Thus, an error does have a particular value,

although the metrologist does not know that value; the uncertainty is a range of values specified by the metrologist to indicate his best knowledge about the likely value of the error.

The phrase "bias uncertainties" has been used rather than the more

commonly used "systematic errors" to express the uncertainty about the

sources of error listed. If the error itself could be evaluated, a correction would be made., The phrase "random error" is used to represent observed deviations of measurements from the mean of a set of

measurements

.

In perusing these pages, the reader will observe that the values for

errors are sometimes shown with plus and minus signs (±) and sometimes without the signs. There is no significant difference between the

two designations, it being mostly a matter of personal choice. Prepared material for this volume came from a number of sources, and no

particular effort was made to bring the use of plus and minus signs into

uniformity. To do so would have required extensive redrafting and retyping .

* NBS Technical Note 262, Accuracy in measurements and calibrations,

1965, edited by W. A. Wildhack, R. C. Powell, and H. L. Mason, issued

June 15, 1965.

#* The concept of "true value" is discussed in some detail by Churchill

Eisenhart in his paper, Realistic evaluation of the precision and accuracy

of instrument calibrating systems, J. Res. NBS 67C, 161 (1963).
Bias Uncertainties :

The uncertainties shown in these tables are typical values and in

general may vary somewhat, depending on the range of frequency, the

magnitude of the measurand (the quantity being measured), or the nature

of the particular device being calibrated. Sometimes the magnitude is

given as a single typical value and sometimes as a range of values. More

details can be obtained from the person(s) listed under Personnel.

Where error flow diagrams were available, they were used in place

of tables.

Random Errors:

In general, the number given for the random error represents approximately three times the estimated standard deviation (3a) for a representative set of measurements.

Total Uncertainty:

The total uncertainty figure represents the sum of the estimated bias

uncertainties and the 3a random errors. Note that in a rather large

number of the radio frequency measurements the random errors are

quite negligible with respect to the bias uncertainties. The terms "limits

of uncertainty" and "limits of error" are often used interchangeably with

"total uncertainty. "

Uncertainty quoted customer :

The uncertainty quoted to the customer is not always equal to the

total uncertainty as described above. It is sometimes larger due to

round-off, and sometimes larger to include an additional margin of

safety in the estimate of possible error. Reporting practice is tending

more and more toward quoting the actual number obtained as above,

rather than the larger figures.

Notes :

The notes include information and comments which are intended to

clarify the diagrams and charts or otherwise, help the reader to understand some aspect of the measurement.
References :

The lists of references are not intended to be complete, but rather to

supply the reader with at least one source of published information concerning the measurement, as made by NBS. Sometimes no such sources

are available. Where references are given, they often include extensive

bibliographies on the subject measurement. Unpublished information

can often be obtained from the personnel whose names are listed.

Personnel :

The name of the person(s) responsible for each measurement is

given. Anyone requiring more detailed information about any of the

measurements is invited to write to the appropriate person at

National Bureau of Standards

Institute for Basic Standards

Boulder, Colorado 80 302

or telephone (303) 447-1000 and ask for the person named.

These names are also listed to give credit to those who helped to

prepare the charts and other information on the various measurements.
MEASUREMENT REPRESENTATION

The Symbol Represents

A measurement technique or device

u Meter

The output of one measurement and input to other measurements ,'

e.g., a calibrated meter having uncertainty u. The uncertainty

is expressed either as a percentage, as a fraction, or as a quantity with dimensions; e.g. "5%", "3xl0" 7 "

, or"lO/isec".

These outputs are usually available to NBS customers.

A measurement output available to NBS customers.

Meter
TIME AND FREQUENCY

STANDARDS

Calculated Time Scales

AT (NBS), SAT(NBS),and UTC(NBS)

Nominal Standard Frequencies,

Daily

Adjustments

Intercomparison

Data

5 MHz

1 pps

5 MHz

n ,\

1 PPS

0, 5000 kc/UTC(NBS) Clock #8

Second P

I Nominal I Pulse

/ Per UTC(NBS)

Second

Ft. Collins ^ i — p.

5 MHz

TV

Comparison
Time and Frequency Standards

Bias Uncertainties:

Source of Uncertainty Fractional Uncertainty

Magnitude of H(x) (3^ limits) 0.3 (parts in 1 1

) Overlap of neighboring transitions 1. Use of H(x) 2 for H

2

(x) 0, 1 Distortion arising from C-field

nonuniformity 0. 5 Cavity mistuning 0. 1 Uncertainty in magnitude of cavity phase

shift 3.

Doppler shifts 1.0

Microwave power level 1.0

Spectral purity of excitation 2.

Second harmonic distortion of servo

modulation 0. 5 Miscellaneous servo system effects 2.0

Multiplier chain transient phase shifts 1.0

Random Errors (one hour averaging, 3^r— )0.5

Total Uncertainty (square root of sum

of squares): 4.7 (parts in 10 )

Notes : Error sources listed here contribute to the uncertainty in determining the frequency of a particular atomic state separation of the free

cesium atom. The fractional uncertainty is given as 3<r- limits for

statistically determined quantities and by estimated extreme limits for

other quantities.

The random error given above refers to the random variations between

successive frequency comparisons (with one hour averaging time) between

the NBS-III cesium beam machine and another highly stable oscillator. The

contribution of NBS-III to the relative fluctuation between the pair of signals

generated can be identified (approximately) because the stability of the

second signal generator is known from comparisons with still other oscillators,

NBS-III cannot be operated continuously -- the NBS time scale is actually

computed from the data obtained by daily intercomparisons between NBS-III

and the signals from five sources (two crystal and three cesium) which do

operate continuously. Data obtained from these intercomparisons may be

6-1
used to adjust the frequencies of the five working sources, when necessary, as shown on page 6.

The standard signals used to control the NBS broadcast stations are

generated from one of the working oscillators. The AT (NBS) time scale

is derived directly from the frequency of the cesium atom, as realized

by NBS-III. The UTC (NBS) scale is generated from a signal having a frequency offset which has been promulgated by the Bureau International

de l'Heure to make the time scale correspond approximately to the UT2

time scale.

USNO and NBS Time Coordination

On 1 October 1968 the epochs of the UTC (NBS) and the UTC (USNO)

time scales were within one microsecond of each other. Since there was

a slight rate difference between the master clocks at these two institutions,

this time coincidence would not have continued. Hence, the USNO and

the NBS agreed to each change their rates by nominally half the difference

on 1 October 1968, and from thenceforth coordinate the rates so that the

master clock at the USNO and the master clock at the NBS would remain

near synchronous. It was initially felt and agreed upon that the time

difference could be kept less than 5 ms.

In the figure (page 6), the abbreviation "pps" means "pulses per

second.

Reference! R. E. Beehler and D. J. Glaze, The performance and

capability of cesium beam frequency standards at the National Bureau

of Standards, IEEE Trans. Instr. Meas., IM-15, 48(1966).

Personnel: D. Halford

D. W. Allan

6-2
TIME AND FREQUENCY

DISSEMINATION - WWVL

19.9 or 20.5 and 20.0 kc/(sec-UTC)

UTC (NBS) Time Scale

AT BOULDER

Horizontal Synchronizing

Pulses

Telephone Comparison

with Ft. Collins Counter

AT FT COLLINS

Telephone Comparison

with Boulder Counter
AT FT. COLLINS:

TIME AND FREQUENCY

DISSEMINATION- WWVB

60kHz SAT (NBS) Time Scale

I PPS SAT(NBS)

I PP/(sec-UTC)

To WWV
TIME AND FREQUENCY

DISSEMINATION - WWV

2.5,5,10,15,20 6 25 Mc/(sec-UTC)

UTC(NBS) Time Scale

IOOkc/(sec-UTC) to WWVL

Error Display

From

WWVL
TIME AND FREQUENCY

DISSEMINATION- WWVH

2.5, 5, 10 a 15 Mc/(sec-UTC)

UTC (NBS) Time Scale

:/(sec- UTC!

lOOkc/(sec-UTC)

100 kc/(sec-UTC)

Corrected Phase (Time

Voice, Time Tick a Audio Tone

Modulation

(« V

»)

10 /jl sec

10
Time and Frequency Dissemination

WWVL, WWVB, WWV, and WWVH:

Bias Uncertainties: Since the signals from all the stations are controlled

by the standards in Boulder, as shown on pages 7-10 , there is no significant long-term bias in the phase of the broadcast signals relative to the

NBS time scales.

Random. Errors ; The phase (time) uncertainties given below are random

fluctuations due to weather-caused changes in antenna impedance and to

operator and equipment limitations.

Station Maximum Phase Error

[re SAT(NBS) or UTC(NBS)]

(microseconds)

WWVL 2.0

WWVB 2.0

WWV 5.0

WWVH 10.0

Total Uncertainty: Same as Random Errors

Notes : Standard time and frequency signals are broadcast from four

radio stations operated by the National Bureau c£ Standards. WWVL, WWVB,

and WWV are located near Ft. Collins, Colorado; WWVH is on the island

of Maui, Hawaii. For detailed description of the information available on

each signal, see the reference below.

The unit of frequency, Hz, is used to denote one cycle per second,

where the second is that defined internationally in terms of a transition in

cesium. The unit, c/(sec -UTC), denotes one cycle per second where the

second is derived from the UTC(NBS) time scale.

The frequency offset from the internationally defined atomic frequency

required to generate the UTC(NBS) time scale is determined annually by the

Bureau International de l

1 Heure (BIH) in Paris. At present the offset is

-300 parts in 10 10

.

SAT(NBS) is a ^Stepped Atomic Time scale based on the atomic frequency

with periodic retardations to approximate UT-2.

Time synchronization between the NBS coordinated time scale UTC(NBS)

and the clocks at the Ft. Collins transmitter sites is checked daily.

10-1
Reference: NBS Standard Frequency and Time Services, Special Pub. 236

(1968). (Revised annually).

Personnel: P. Viezbicke

10-2
DIRECT COiMPARISON:

In addition to obtaining time information from the broadcast signals,

one can also make direct comparisons between the NBS clocks at Boulder

and a portable clock.

Bias Uncertainties: See Notes

Random Errors: See Notes

Total Uncertainty: See Notes

Uncertainty quoted customer: See Notes

Notes: Comparison between AT(NBS) and the customer clock can be

made with a precision of about 1 n sec. and an accuracy of about 100 n sec

Reference: D. W. Allan, R. L. Fey, H. E. Machlan, J. A. Barnes,

An ultraprecise time synchronization system designed by computer

simulation, Frequency 6_, #1, 11 (1968).

Personnel: D. W. Allan

10-3
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11
Cavity Wavemeters

100 MHz - 90 GHz

See Error Flow Diagram, page 11

Bias Uncertainties : Random Errors :

Total Uncertainty :

Uncertainty quoted customer :

Notes: None

Reference : C. G. Montgomery, Techniques of microwave measurements,

Radiation Laboratory Series, No. 11, pp. 291-293(1947).

Personnel : R. E. Larson

C. K. S. Miller

11-1
STABILITY OF STABLE OSCILLATORS AND OTHER

SIGNAL SOURCES: FREQUENCY, PHASE, TIME , AND AMPLITUDE STABILITY

Carrier Frequency : Hz - 12.4 GHz

Frequency Domain: |0" 6 Hz- I06 Hz Fourier Frequency

Time Domain I0" 6

s - I0 6s Time Interval

Signal to be Measured

Reference Derived From Stable Standards

Deviations

at Fourier Frequencies f

j

or at Times t^

Stability

of Customers Device

(Frequency, Phase, Time,

and /or Amplitude )

12
Stability of Stable Oscillators and Other

Signal Sources: . Frequency, Phase, Time,

and Amplitude Stability

Carrier Frequency: Hz - 12.4GHz

Frequency Domain: 10 Hz - 10 Hz Fourier Frequency

Time Domain: 10~"s - 10 s Time Interval

Bias Uncertainties : Less than 3dB typical, to as low as O.ldB

Random Errors : Less than 3 dB typical, to as low as . 1 dB

Total Uncertainty: Less than 5 dB typical, to as low as 0. 2 dB

Uncertainty quoted customer: Same as Total Uncertainty.

Notes : These calibrations can be performed on quartz crystal

oscillators, atomic frequency standards, signal generators, frequency

synthesizers, frequency multiplier chains, frequency dividers,

amplifiers, buffers, phase shifters, and in general any device which

generates or processes a frequency, phase, or time signal. Spectrum

analysis can be done directly at Fourier frequencies f greater than

1 hertz, with an analyzer bandv/idth as narrow as 1 hertz. The entire

range of frequency domain stability can be obtained by Fourier

transformation of time domain data.

References : D. W. Allan, Statistics of atomic frequency standards,

Proc. IEEE, 54, 221(1966), and L. S. Cutler and C. L. Searle,

Some aspects of the theory and measurement of frequency fluctuations

in frequency standards, Proc. IEEE, 54, 136 (1966).

Personnel : J. H. Shoaf

D. Halford

12-1
RF POWER IN COAXIAL SYSTEMS

10 - 4000MHz

1-IOmW Power Level

BOLOMETER CALIBRATION FROM

DRY LOAD CALORIMETRIC MEASUREMENT

0.26

0.35

o//o

Standord

Transfer Bolometer

1 10 to 1000 MHz

1000 to 4000 MHz

13
RF Power in Coaxial Systems

DRY LOAD CALORIMETRIC MEASUREMENT:

10 - 4000 MHz

50 mW - 5W

Bias Uncertainties:

10 - 1000 MHz 1000 - 4000 MHz

0.04% 0.08%

negligible negligible

0.05 0.10

0.02 0.02

0.15 0.15

negligible negligible

0. 26% 0. 35%

Calorimeter efficiency

VSWR mismatch

RF - dc substitution

dc power

Feedback loop error

Random Errors ;

Total Uncertainty :

Uncertainty quoted customer: See Notes

Notesj Ordinarily this measurement is not offered to the public as a service, but is used for international comparisons and to calibrate

standard transfer bolometers which are in turn used to calibrate

working standard bolometers for the NBS Electronic Calibration Center

Reference : M. L. Crawford, A new RF - dc substitution calorimeter

with automatically controlled reference power, IEEE Trans. Instr.

Meas. IM-17 , 378 (Dec. 1968).

Personnel: P. A. Hudson

13-1
RF Power in Coaxial Systems

TRANSFER BOLOMETER CALIBRATION BY DIRECT COMPARISON:

At 10 mW power level

Bias Uncertainties:

The bias uncertainties are taken to be equal to the total error estimated for the calibration of the standard transfer bolometer by the dry

load calorimeter. See page 13-1.

Random Errors: Random errors are less than 0. 1%.

Total Uncertainty:

10 - 1000 MHz: 0.40%

1000 - 4000 MHz: 0. 50%

Uncertainty quoted customer: See Notes

Notes : Ordinarily this measurement is not offered to the public as a service, but is used to calibrate working standard bolometer units for

use in the NBS Electronic Calibration Center.

Reference : None

Personnel: P. A. Hudson

13-2
RF Power in Coaxial Systems

BOLOMETER CALIBRATION BY DIRECT COMPARISON:

At 1, 3, 10 mW power levels

Bias Uncertainties:

Bias uncertainties are taken to be the total estimated error in the

calibration of the working standard bolometer. See page 13-2.

Random Errors : Random errors in calibration of customer units bydirect comparison are less than 0. 15%.

Total Uncertainty:

10 - 300 MHz: 0. 50%

300 - 1000 MHz: 0. 65%

1000 - 4000 MHz: 0.85%

Uncertainty quoted customer:

10 - 300 MHz: 1%

300 - 1000 MHz: 1%

1000 - 4000 MHz: 1%

References : P. A. Hudson, A precision RF power transfer standard,

IRE Trans. Instr. 1-9, 280 (I960).

R. F. Desch and R. E. Larson, Bolometric microwave power calibration techniques at the National Bureau of Standards, IEEE Trans. Instr.

Meas. IM-12, 29 (1963).

Personnel: F. X. Ries

13-3
RF POWER IN COAXIAL SYSTEMS

dc - 4000MHz

2 - 100 W Power Level

FLOW CALORIMETER MEASUREMENT

0.38%

Working

Standard

:

Bolometer- Coupler

Units

>1 %

Calibrated

Power

Meter

* Error Limits Are Often Quoted As Greater Than I % , Since Many Meters Calibrated Are Inherently Less

14
RF Power in Coaxial Systems

dc - 4000 MHz

2 - 100 W Power Level

FLOW CALORIMETRIC MEASUREMENT :

2 - 100 watts

Bias Uncertainties:

dc power 0. 2%

RF - dc substitution 0. 10

Calorimeter efficiency 0.05

Thermal drift and flow rate variations 0.15

Random Errors: See Notes 0.06

Total Uncertainty: 0.38%

Uncertainty quoted customer: See Notes

Notes : Ordinarily this measurement is not offered to the public as a service, but is used only for international comparisons and to calibrate

working standard bolometer-coupler units for use in the NBS Electronic

Calibration Center.

The random error given here is the maximum observed variation.

Reference : None

Personnel: P. A. Hudson

14-1
. RF Power in Coaxial Systems

FLOW CALORIMETRIC MEASUREMENT, DIRECT COMPARISON:

2 - 100 watts

Bias Uncertainties:

Uncertainty of working standard 0. 5%

VSWR mismatch and errors in meter to be

calibrated 0. 3

Random Errors: 0.2

T otal Uncertainty: 1 . 0%

Uncertainty quoted customer: 1%

Notes : Errors inherent in the meter to be calibrated can be more than

the allowance made here, that is 0. 3%. Thus, occasionally the

uncertainty quoted the customer is greater than 1%.

Reference : None

Personnel: F. X. Ries

14-2
MICROWAVE POWER: COAXIAL BOLOMETER UNITS

Type N Connector, Male : 4 - 10 GHz

Precision Connector (GPC - 14) : 4-8.5GHz

I -lOmW Power Level

ADAPTER METHOD OF MEASUREMENT

*7w

\

7 2 Vw

0.72- 1.54%

Effective Efficiency of Coaxial Unit

Effective Efficiency of Waveguide Standard Unit

Efficiency of Adapter as Used In Step ( \ )

15
Microwave Power: Coaxial Bolometer Units

Type N Connector, Male: 4-10 GHz

Precision Connector (GPC-14): 4-8.5 GHz

1-10 mW Power Level

ADAPTOR METHOD OF MEASUREMENT:

Bias Uncertainties:

Random Errors : ) See Error Flow Diagrams, pages 15-2 and 15-3

T otal Uncertainty:

Uncertainty quoted custome r: . 8% to 1 . 8%

Notes : This measurement permits the comparison of a coaxial bolometer

unit directly with a waveguide standard bolometer unit. Thus, it is not

necessary to develop a calorimetric technique for calibrating working

standard coaxial bolometer units in this frequency range. See reference.

The uncertainty in the waveguide standard in the frequency range 4 to

7.05 GHz (where the impedance method of measurement is used) is

0.75%. In the frequency range 7.05 to 10 GHz (where the calorimetric

method of measurement is used), the uncertainty in the waveguide

standard is 0.2%.

Symbols appearing in the error flow diagrams are defined in the

reference below.

Reference : G. F. Engen, Coaxial power meter calibration using a waveguide standard, J. Res. NBS 70C, 127, (1966).

Personnel: R. F. Desch

15-1
MICROWAVE POWER: COAXIAL BOLOMETER UNITS

ERROR FLOW DIAGRAM FOR CALIBRATION TRANSFER SYSTEM

FOR TYPE N CONNECTORS

ADAPTOR METHOD

REFERENCE

VOLTAGE

± O.OI %

STANDARD

RESISTOR

I ± 0. I °/<

BRIDGE ARM

RESISTANCE

±0.01 %

BRIDGE CURRENT

MEASUREMENT

±0.03%

| ±0.06%

±0.01% DIGITAL

VOLTMETER

SELF BALANCING

-HBOLOMETER BRIDGES

±0.09% ±OJ/iW

±0.02 7o±0.l/zW FINITE GAIN

± 0.1 /iW

INSTABILITY

DIFFERENCE IN m2a

ANDm 2 B » F0R TYPE

N ONLY, ADD ±0.22%

TO LIMITS OF ERROR

NEGLIGIBLE

TUNING

OF Tx

TUNING

OF T

±0.01%

CONNECTOR

DISSIPATION

±0.22

ADDITIONAL ERROR IN CALIBRATING A TUNED

WAVEGUIDE STANDARD

(12.4 - 18.0 GHz)

±0.20%

±0.38%

WAVEGUIDE WORKING STANDARD

FREQ(GHz) LIMITS OF ERROR (%)

4.0 - 7.05 ±0.75 (IMPEDANCE)

7,05-12.4 ±0.20 (CALORIMETER)

12.4-18.0 ±0.68 /CALORIMETER

V 8 REFLECTOMETER)

ERROR IN

vrri| i7i2 ^UE

TO BRIDGES

±0.10%

I

±0.22%

POWER AND

FREQUENCY

INSTABILITY

±0.15%

±0.01%

1

CALIBRATION TRANSFER

LONG METHOD

FREQ.(GHz) LIMITS OF ERROR (%)

4.0- 7.05

7.05 -ro.o ± 1.54

±0.99

ERROR INK|ANDK2

DUE TO BRIDGES

±0.18 %

±0.18%

1

TEMPERATURE

INSTABILITY AND

RESOLUTION

±0.02%

TEMPERATURE

INSTABILITY

AND

RESOLUTION

±0.10%

APPROXIMATION

TO 4.0-7.05 GHz ± 1.6%

CUSTOMER 7.05-10.0 GHz ±1.0%

CALIBRATION OF ADDITIONAL

BOLOMETER UNITS USING

P2

= K, P4~ K 2 P3

SHORT METHOD

FREQ.(GHz) LIMITS OF ERROR (%)

4.0 -7.05

7.05-10.0

± 1.79

± 1.24

NEGLIGIBLE

POWER AND

FREQUENCY

INSTABILITY

±0.05%

I

CONNECTOR

DISSIPATION

TO CUSTOMER

4.0- 7.05 GHz ± 1.8%

7.05 - 10.0 GHz ± 1.3%

15-2
MICROWAVE POWER: COAXIAL BOLOMETER UNITS

ERROR FLOW DIAGRAM FOR CALIBRATION TRANSFER SYSTEM

FOR PRECISION CONNECTORS (GPC-14 STOPS AT 8.5 GHz)

ADAPTOR METHOD

STANDARD

RESISTOR

±0.01%

f ± 0.01%

REFERENCE ±0.01%

VOLTAGE

BRIDGE CURRENT

MEASUREMENT

± 0.03%

digital

voltmeter

BRIDGE ARM

RESISTANCE

± 0.01 %

| ±0.06%

SELF BALANCING

BOLOMETER BRIDGES;

±0.09% ±O.I^.W

±0.02%±0.l/iW FINITE GAIN

± O.I/iW

INSTABILITY

NEGLIGIBLE

ADDITIONAL ERROR IN CALIBRATING A TUNED

WAVEGUIDE STANDARD

(12.4 - 18.0 GHz)

TUNING

OF Tv

TUNING

OF T,

±0.20%

±0.38%

WAVEGUIDE

FREQ.(GHz)

4.0-705

7.05-12.4

12.4-18.0

WORKING STANDARD

LIMITS OF ERROR (%)

±0.75 (IMPEDANCE)

±0.20 (CALORIMETER)

±0.68/ CALORIMETER S

\ REFLECTOMETER

±0.01%

CONNECTOR

DISSIPATION ±0.15%

POWER AND

FREQUENCY

INSTABILITY

±0.01%

CALIBRATION TRANSFER

LONG METHOD

FREQ. (GHz) LIMITS OF ERROR (%)

4.0 -7.05

7.05-12.04

12.4 - 18.0

± 1.27

± 0.72

± 1.20

ERROR IN K| AND «2

DUETO BRIDGES

± 0.13%

±0.13%

TEMPERATURE

INSTABILITY AND

RESOLUTION

±0.02%

3_

ERROR IN vm| m2 DUE

TO BRIDGES

±0.05%

TEMPERATURE

INSTABILITY

AND

RESOLUTION

± 0. 10 %

APPROXIMATION

lu

T0 4.0-7.05 GHz ± 1.3%

Customer 7.05-12.4 ghz ±0.8%

12.4 - 18.0 GHz ±1.2%

CALIBRATION OF ADDITIONAL

BOLOMETER UNITS USING

P 2

= K| P4- K2P3

SHORT METHOD

FREQ. (GHz) LIMITS OF ERROR (%)

4.0 -7.05

7.05-12.4

12.4— 18.0

± 1.47

± 0.92

± 1.40

i

NEGLIGIBLE POWER AND

FREQUENCY

INSTABILITY

±0.05% CONNECTOR

DISSIPATION

TO CUSTOMER

4.0 - 7.05 GHz ± 1.5 %

7.05-I2.04GHZ ± 1.0 %

12.4-18.0 GHz ± 1.5 %

15-3
MICROWAVE POWER : WAVEGUIDE BOLOMETER UNITS

WR 28 : 26.5 - 40.0 GHz

WR 42- 18.0- 26.5GHz

WR 62 12.4- 18.0GHz

WR 90= 8.2- 12.4GHz

WR 112' 7.05-IO.OGHz

10 mW Power Level

MICROCALORIMETRIC MEASUREMENT

0.3%

Tj

Q of Working Standard

Bolometer Units

0.2 %

TJe of Working Standard

V

=

V

K

c

=

rf power dissipated in element

rf power dissipated in unit

bolometric power ( substituted dc.

)

rf power dissipated in unit

bolometric power (substituted dc) 2

= (l-ITI )r)

rf power incident on unit e

bolometric power in sidearm (substituted dc)

rf power incident on non -reflecting main-arm load

16
Microwave Power

WR 28

WR 42

WR 62

WR 90

26. 5 - 40 GHz

18. - 26. 5 GHz

12.4 - 18. GHz

8. 2 - 12.4 GHz

10 mW Power Level

MICROCALORIMETRIC MEASUREMENT:

Bias Uncertainties:

Random Errors: See Error Flow Diagram, p. 16-2

Total Uncertainty:

Uncertainty quoted customer: See Notes

Notes : Ordinarily this measurement is not offered to the public as a service, but is used only for international comparisons and to calibrate

working standard bolometer units for use in the NBS Electronic

Calibration Center.

Reference : G. F. Engen, A refined X-band microwave microcalorimeter,

J. Res. NBS 63C, 77 (1959).

16-1
MICROWAVE POWER: WAVEGUIDE BOLOMETER UNITS

ERROR FLOW DIAGRAM FOR REFERENCE STANDARD

MICROCALORIMETRIC MEASUREMENT

WR90 AND WR62

STANDARD RESISTOR

±0.01%

BRIDGE CURRENT

MEASUREMENT

± 0.03%

REFERENCE

VOLTAGE

±0.01% ±0.01% DIGITAL

VOLTMETER

i

±0.06%

f

SELF-BALANCING

BOLOMETER BRIDGE

±0.09% ±O.I/iW

BRIDGE ARM

RESISTANCE

±0.01% ±0.02%±0.I/aW FINITE AMR

GAIN ±O.I/iW

INSTABILITY

<

±0.01 %

; ±0.09%

(WR90)

MICROPOTENTIOMETER

INSTRUMENTATION

± 0.10% (WR 90)

± 0. 13% (WR 62)

THERMOPILE

NONLINEARITY ±0.12%

(WR62)

TEMPERATURE

INSTABILITY

FLANGE LOSS

±0.07%(WR90)

±0.I2%(WR62)

MICROCALORIMETER

CALIBRATED BOLOMETER UNIT

EFFECTIVE EFFICIENCY

± 0.20% (WR 90)

± 0.30% (WR 62)

±0.03%(WR90^

±0.05%(WR62) CALORIMETRIC

SUBSTITUTION

ERROR

WAVEGUIDE

WORKING STANDARD

16-2
Microwave Power

MICROCALORIMETRIC MEASUREMENT, DIRECT COMPARISON

METHOD:

Bias Uncertainties:

Calorimetric measurement of

working standard 0.2 to 0.3%

RF power, temperature, and

frequency stability 0. 02

dc power 0. 1 Flange dissipation and misalignment 0. 05 to 0. 1 VSWR mismatch (for 0. OK |r| <0.20) 0.03 to 1.23

Random Errors: Typical value 0. 04

Total Uncertainty:(for 0. 01 < | V | < 0. 20) 0. 40 to 1. 75%

Uncertainty quoted customer: 0. 5 to 1.8%

Notes : This measurement method is used for K only. (See definition

below. )

| T | is the absolute value of the complex reflection coefficient of the

bolometer unit.

An error flow diagram for the measurement in the WR 90 waveguide size

is given on page 16-5.

In this document the term "bolometer element" will refer to the thermoelement in which the RF power is detected. "Bolometer mount" will

refer to the waveguide in which the element is mounted, and "bolometer

unit" will refer to the combination. A "bolometer-coupler unit" is a bolometer unit mounted on an arm of a directional coupler.

The definitions of efficiency ( rj )

, effective efficiency ( -q ), and calibration factor (K ) of bolometer units are as follows:

b

RF power dissipat ed in bolometer element

RF power dissipated in bolometer unit

bolometer power (subst i

t

uted dc in the bolometer unit)

e RF power dissipated in bolometer unit

bolometer power (substituted dc) . 2

b RF power incident on unit e

16-3
The calibration factor (K ) for a bolometer-coupler unit is: c bolometer p ower i n the sidearm (substi tuted dc

)

c RF power incident on a non- reflec ting main-arm load

The nominal 10 mW power level is for direct incidence on the unit

attached to the main arm.

Bolometer-coupler units are calibrated at the power level appropriate

to the coupler.

Symbols appearing in the error flow diagram are defined in the reference

below.

Reference : R. F. Desch and R. E. Larson, Bolometric microwave

power calibration techniques at the National Bureau of Standards, IEEE

Trans. Instr. Meas., IM-12, 29 (1963).

Personnel: R. F. Desch

16-4
GOo < q:

^=: en. ^> 4 S oo CD

<_S> ~ — CO

cj? ^ — en

LL-i <=> £ <c _ = C5 o> o

°^ r±z c_s v—

0=1 ce: -=J

L ^ °^

«J-»

q^ S

fp.

<-5

_

ce:

<*= 1 ^ A OS

A OS l-l_l UJ !_•_ seo

3E jg cs CS

co CO CO

>_ 33 S3 =S

CO CO CO CO ^^ ^o

Lj_i ° CD CS «-^ ^^ ^m ^__ ^t^m CO c=> "" C*nI La— • OS —.

FECTIVE

EF

ERROR ±

OS

l_i_J

OQ

UNIT I

FACTOR ERROR

11% +1

BOLOMETE

IIT IN

FACTOR

IF

ERROR

±1.18%

BOLOMETE

NIT

EFFICIENCY

OF

ERROR

±1.61%

^E. <_«> t=J 1

UNIT E

MITS

01

aseo

OUPLEF BRATIO MITS ±.

BRATEO LIBR

ATI

IMITS .81%

BRATEO

Ul

ECTIYE IMITS .829 T

ce i H CO

—

—; ««c — +1

— Lt: ~~' +i

l_l_l ^k ^K «E C-3 -* . 1— «—«i CO CO CO CO

"-« CD

k i cs oe ^p

•^p p^- ^^ ^c o^- PO

GS p^ ^r

CO C-vl +1

r—.

r— +i

+1 cs cs

-^p -35 kp ^p -~P p^~ p~^ p^ p~^ o^ ^p p^

C^l ^—> U"3 CO p~^ ^mm TM ** 63 <=> ^?#- CS + +1 +l H +i

4-1 +1 3-

>— CO

h— ^

l_l_l cs 3 CO OS "=j >_ __ -\p 2: 3E o s oa z LU <=> VI cs CO cs CO

oe00 ^

j^ CS

CO hZ cs ,_ CO

CO

OS- C~sl OS CO • "-j 1—i y|

_ ^— <Q- ^^ +1 oe c=>

i_i_i «—

i*j e^j

OS ^j

LJ~ oa l_l_l cs 5s2 ^ cs <=>

JJ? +1 OS ljj O0 ,_ -^ -^r " * . C—3 ^^ ^ oe CO a: a^ VI VI ^^ *"*- ^5

<—| ^ OS -^ » ^^ ^_

eo

TEMPERA

AND

l_i_l

—

UNCERTA

ERRO ±01

\P o . O ^^5" ^p o^ o^ p^ p\ p^ p^

^** ^~ C3 LTS evi c\ =: <=! «—;

CS ^- + +1 +1 +1 +1 +1

16-5
Microwave Power

MICROCALORIMETER MEASUREMENT, REFLECTOMETER METHOD:

Bias Uncertainties:

Random Errors:

See Error Flow Diagram,

page 16-7

Total Uncertainty:

Uncertainty quoted customer:

Notes: See notes for Direct Comparison method (see p. 16-3).

This measurement method is used for 17 and K only. (See definitions

e b

on p. 16 -3.

)

The estimated uncertainty in a measurement of K is actually about

0.1% higher than that for v , because reflection at the waveguide

junction has an effect in that case. The uncertainty is still considerably

less than 1%, however.

Symbols appearing in the Error Flow Diagram are defined in the

reference below.

The self -balancing bolometer bridge (see p. 16-7) with an uncertainty

at 0. 10% contributes 0.20% to the total uncertainty because the bridge

is used more than once in the power measurement.

Reference: G. F. Engen, A transfer instrument for the intercomparison

of microwave power meters, IRE Trans. Instr., 1-9 , 203 (1960).

Personnel: N. T. Larsen

R. F. Desch

16-6
MICROWAVE POWER: WAVEGUIDE BOLOMETER UNITS

ERROR FLOW DIAGRAM

MICROCALORIMETRIC MEASUREMENT,

REFLECTOMETER METHOD

WR 284, WR 187, WR 137, WR 112, WR90, WR 62, WR 42, WR 28

BOLOMETER UNIT EFFECTIVE EFFICIENCY

REFERENCE STANDARD

IMPEDANCE SYSTEM CALORIMETER

WR 2841 WR H2 1 +nono/ WR 62 ±0.30%

WR 187 Y ±0.75% WR 90 J - u-^u /o WR 42 ±0.25%

WR 137 J WR 28 ±0.31%

±0.20% TO

SELF-BALANCING ±0.75%

BOLOMETER BRIDGE

±0.10%

±0.20%

< CALIBRATED BOLOMETER

UNIT

EFFECTIVE EFFICIENCY

LIMITS OF ERROR

±0.57% TO ±1.23%.

TUNING T

y ±0.01%

±0.01%

TO

CUSTOMER

1

l TEMPERATURE

INSTABILITY AND

RESOLUTION ±0.05%

±0.05%

'

POWER AND FREQUENCY

INSTABILITY ±0.01%

±0.01%

FLANGE LOSS

±0.10% TO ±0.20%

±0.10%

TO ±0.20%

i CALIBRATED BOLOMETER

UNIT

CALIBRATION FACTOR

LIMITS OF FRROR

UNCERTAINTY IN MISMATCH

ERROR CORRECTION

±0.01% TO ±0.43%

±0.01%

TO

CUSTOMER

TO ±0.43%

±0.58% T ±1.66%

16-7
MICROWAVE POWER: WAVEGUIDE BOLOMETER UNITS

WR 137= 5.85 - 8.20 GHz

WR 187: 3.95- 5.85 GHz

WR 284 ; 2 60- 3.95 GHz

10 mW Power Level

IMPEDANCE METHOD OF MEASUREMENT

V =

rf power dissipated in element

rf power dissipated in unit

bolometric power (substituted dc

rf power dissipated in unit

0.5%

rj of Barretter Units

0.8 %

of Working Standard

or Customer s Barretter Units

1.0%

Kc of all Types

of Units

ne : 1.2%

K b : 1.6%

Vnd K

b Thermistor Units

V

bolometric power (substituted dc) mi9t -(I-|IT)?7

rf power incident on unit

bolometric power in sidearm (substituted dc)

rf power incident on non-reflecting main -arm load

17
Microwave Power

WR 137: 5. 85 - 8. 20 GHz

WR 187: 3. 95 - 5. 85 GHz

WR 284: 2. 60 - 3. 95 GHz

1 mW Power Level

IMPEDANCE METHOD OF MEASUREMENT:

Bias Unc ertainties

:

R andom Errors : } See Error Flow Diagram, page 17-2

Total Uncertainty:

Uncertainty quoted customer: 1 %

Notes : The impedance method actually measures only tj , the efficiency

of a bolometer unit. The limits on the effective efficiency of the working standard are obtained from the measured efficiency, rj , and an

estimate of the RF-dc substitution error. The standard is then used, as shown on page 17, to calibrate the customer's units when ri , K , or K

• a • a

e b c

is desired.

Symbols appearing in the Error Flow Diagram are defined in reference

below.

Reference : G. F. Engen, A bolometer mount efficiency measurement

technique, J. Res., NBS, 65C, 113 (1961).

Personnel: R. F. Desch

17-1
MICROWAVE POWER: WAVEGUIDE BOLOMETER UNITS

ERROR FLOW DIAGRAM FOR WORKING STANDARD

IMPEDANCE METHOD

WR284, WRI87, WRI37

STANDARD

RESISTOR

REFERENCE

VOLTAGE

±0.01%

±0.01%

BRIDGE CURRENT

MEASUREMENT

±0.03%

BRIDGE ARM

RESISTANCE

±0.01%

±0.01%

DIGITAL

VOLTMETER

±0.06%

SELF-BALANCING

BOLOMETER BRIDGES

±0.09% ±O.I/iW

TUNING OF TUNING OF

T"U ELIMINATED

NEGLIGIBLE

TEMPERATURE

POWER AND

FREQUENCY

INSTABILITY

BOLOMETER

RESISTANCE

±0.01%

±0.10 % i ***

CABLE

RESISTANCE

±0.02%

±0.02%±0.I/aW FINITE AMPLIFIER

GAIN ±O.I/iW

INSTABILITY

±0.10%

TUNING OF

TV

TUNING OF

TY

T

±0.015%

MEASUREMENT

OF SIGNAL

AMPLITUDES

±0.20%

±0.05%

USE OF

APPROXIMATE

METHOD

CALIBRATED BARRETTER UNIT

EFFICIENCY

±0.50%

±0.005%

*-*-*n±o.05%

*

DC - RF

SUBSTITUTION

ERROR

±0.25%

±0.05%

±0.50%

IMPERFECT NULL

IN AUXILLIARY

CHANNEL

CALIBRATED BARRETTER UNIT

EFFECTIVE EFFICIENCY

±0.75%

WAVEGUIDE

WORKING STANDARD

17-2
Microwave Power

IMPEDANCE METHOD OF MEASUREMENT,

DIRECT COMPARISON METHOD:

Bias Uncertainties: \

Random Errors: See Error Flow Diagram, page 16-5

Total Uncertainty: ,

Uncertainty quoted customer: 1.5%

Notes: This measurement is used to obtain K for bolometer- coupler

c units with any type of element.

Reference: None

Personnel: R. F. Desch

17-3
Microwave Power

IMPEDANCE METHOD OF MEASUREMENT,

REFLECTOMETER METHOD:

Bias Uncertainties:

Random Errors : ) See Error Flow Diagram, page 16-7

Total Uncertainty:

Uncertainty quoted customer: 7? fo r | T | < 0.01: 1%

K, for |r| < 0. 2 : 1%

b

Notes: This measurement is used to obtain n and K, for bolometer

e b

units with thermistor-type elements.

Referenc e : None

Personnel: R. F. Desch

17-4
RF PEAK- PULSE POWER IN COAXIAL SYSTEMS

300 - 500 MHz

950 - 1200 MHz

Pulse Duration • 2-IO^.sec

Pulse Repetition Rate ; 100-1600 pps

Maximum Duty Factor : 33 x 10 —

Peak- Pulse Power ! I.OmW -3.0kW

Calibrated

Pulse Power

Meter
Peak-Pulse Power in Coaxial Systems

300 - 500 MHz

950 - 1200 MHz

Peak-Pulse Power: 1. mW - 3. kW

Bias Uncertainties:

RF power measurement

a. signal level (CW) 1%

b. direction coupler calibration 1 c. comparison system 1 Random Errors : negligible

Total Uncertainty: 3

%

Uncertainty quoted customer : 3 %

Notes : This measurement can be made with the uncertainties stated

only on the following conditions:

(1) Pulse duration must be between 2 and 10 microseconds.

(2) Pulse repetition rate range: 100 to 1600 pps.

(3) The duty factor (duty cycle) must be less than 33 x 10

(4) The peak-pulse power range must be between 1. mW and

3. kW.

Referenc es : P. A. Hudson, W. L. Ecklund and R. A. Ondrejka,

Measurement of RF peak-pulse power by a sampling-comparison method,

IRE Trans. Instr., 1-11 , 280 (1962).

Peak-pulse power calibrations initiated, NBS, RSL, Engineering

Division, IEEE Trans. Microwave Theory and Tech., MTT-1_4, 47 (1966),

Personnel : P. A. Hudson

P. A. Simpson

18-1
NOISE TEMPERATURE

Coaxial Noise Generator at 3MHz

75 K to 30,000 K

0.2%

Cold Reference

Standard

0.2%

Hot Reference

Standard

1%

Calibrated

Noise Generator

19
NOISE TEMPERATURE

COAXIAL NOISE GENERATOR AT 3MHz

75 K TO 30, 000 K

THERMOMETER

CALIBRATION

±0. 04 K

THERMOMETER

BRIDGE

CALIBRATION

± 0. I K

TEMPERATURE

GRADIENTS

±0.0 1 K

TRANSMISSION

LINE LOSS

+ 0.04K

NBS REFERENCE NOISE GENERATOR, COLD (77K)

± 0.1 1 K, ± 0.2% OFTx

TEMPERATURE

STABILITY

±0.01 K

THERMOMETER

CALIBRATION

±0.08 K

THERMOMETER

BRIDGE

CALIBRATION

±0.08K

TEMPERATURE

GRADIENTS

+ 0.5K

TRANSMISSION

LINE LOSS

± 0.02K

NBS REFERENCE NOISE GENERATOR, HOT (373 K)

± 0.70 K, ± 0.2% OF Tx

TEMPERATURE

STABILITY

± 0.02 K

COMPARISON

RADIOMETER

(3(rt ±0.2% OF Tx

ATTENUATOR

CALIBRATION

±0.08% OF Ty

SOURCE

IMPEDANCE

ERROR

± 0.08% OFT,

\t H

TOTAL BIAS UNCERTAINTY : APPROX. ± 0.6% OF T„

RANDOM UNCERTAINTY (3<r) : APPROX. ± 0.4 % OF Tx

CUSTOMER'S MAX. UNCERTAINTY: APPROX. ± 1% OF Tx

19-1
Noise Temperature

Coaxial Noise Generator at 3 MHz

75 K to 30, 000 K

Bias Uncertainties: Approximately +0.6%

Random Errors: Approximately +0.4%

Total Uncertainty: Approximately + 1%

Uncertainty quoted customer: Actual total uncertainty as computed from

the measurement data, using the error equation for the measurement

process

.

Notes: The uncertainties on the diagram (page 19-1) are typical values.

Two values are given for each reference generator. The first is the

actual uncertainty in the noise temperature of the reference generator;

the second is the contribution by that reference generator to the total

uncertainty in the measured value of the unknown noise temperature, T . x

Reference: M. G„ Arthur, C. M. Allred, andM. K. Cannon, A precision

noise-power comparator, IEEE Trans. Instr. Meas., IM-13, 301 (1964).

Personnel: M. G. Arthur

19-2
EFFECTIVE NOISE TEMPERATURE

WAVEGUIDE NOISE SOURCE AT 9GHz

11,000 K

±4.0 K NBS Reference Noise Standard

± 109.4 K NBS Working

Noise Standard

20
EFFECTIVE NOISE TEMPERATURE

FOR ARGON NOISE SOURCE, OR

WAVEGUIDE NOISE SOURCE AT 9 GHz

OPERATING AT 11,000 K

THERMOCOUPLE

CALIBRATION

± 0.3 K

AVERAGE OF

THERMOCOUPLES

AND TEMPERATURE

MEASUREMENTS OF

NOISE GENERATOR

±0.7K

I

DETERMINING

GRADIENT

CORRECTION

VALUES

±3.0K

NBS REFERENCE NOISE

±4.0 K STANDARD

8a

(CALBRATION OF ATTENUATOR,

BALANCE AND OPERATOR)

± O.OIdB

8TA

ATTENUATOR AMBIENT

TEMPERATURE

t 2.0 K

REFLECTOMETER

MEASUREMENT

±5%

£

COMPARISON RADIOMETER

THESE ARE

PERCENTAGES OF ~ c ° THE LIMITS OF (22 5%)

ERROR IN AN NBS

WORKING STANDARD

MISMATCH EFFECTS

±19. 3K

±43.9 K

(40.1%)

t

±2CK3K

(18.3%)

i

±1.6 K

(15%)

t

(17.6%)

NBS WORKING STANDARD ±109.4 K

SA

(CALBRATION OF ATTENUATOR , BALANCE AND OPERATOR)

+ 0.007 dB

MISMATCH (REFLECTION

COEFFICIENT MAGNITUDE OF

CUSTOMERS ITEM LESS THAN 0.02)

+ 8.6 K

COMPARISON RADIOMETER

, , THESE ARE THE PERCENTAGES

OF THE LIMITS OF ERROR IN THE FINAL CALIBRATION

±|7.4K

(12.8%)

_£

±II0.4K

(80.9%)

A

±8.6 K

( 6.3%)

i

CUSTOMER S INTERLA80RAT0RY STANDARD ± 136. 4K

20-1
Effective Noise Temperature

For Argon Noise Source, or Waveguide Noise Source at 9 GHz

11, 000K

B ias Uncertainties:

Random Errors : } See page 20-1

Total Uncertainty:

Uncertainty quoted customer: Same as Total Uncertainty.

Notes : The uncertainties on the diagram (page 20-1) are typical values

of systematic error at 9. GHz. The error limits depend in a very

complicated way on several parameters.

Reference : J. S. Wells, W. C. Daywitt and C. K. S. Miller, Measurement of effective temperatures of microwave noise sources, IEEE Trans

Instr. Meas. , IM-13, 17 (1964).

Personnel: C. K. S. Miller

20-2
RF VOLTAGE, COAXIAL SYSTEMS

30 kHz - 1000 MHz

0.1 -300 Volts

i%

Calibrated Thermal

Voltage Converter (TVC)

Working Standard

TVC

0.05% (

I MHz ) 0.1 % ( 3, 10 MHz)

0.2 %

I %

30 MHz ) 100 MHz ) 0.05% ( I MHz)

0.1 % ( 3, 10 MHz)

0.2% ( 30 MHz)

I Calibrated Customer

Voltmeter

1 % ( 300-500 MHz!

5 % ( 700- 1000 MHz'

Working Standard

TVC

3 % ( 300- 400 MHz)

5 % ( 500 MHz)

7% ( 700 -1000 MHz)

Calibrated Customer

Vo I tmeter

21
RF Voltage (cw) in Coaxial Systems

30 kHz - 1000 MHz

0. 1 - 300 Volts

BOLOMETER BRIDGE MEASUREMENT :

A. Frequencies 30 kHz - 100 MHz

Bias Uncertainties:

dc voltages and resistances 0.061%

RF source drift 0. 020

Galvanometer noise 0. 050

Stability of interlaboratory standard resistor 0. 010

Short time thermal effects on standard resistor 0. 005

Random Errors (3g): 0.251

Total Uncertainty: 0. 397%

B. Frequencies 100 - 1000 MHz

Analysis similar to the above yields the following estimated error

limits

Frequency Total Uncertainty

(MHz) ^ (%)

100 1 300, 500 1 700, 1000 5

Uncertainty quoted c ustomer: See Notes

Notes : Ordinarily this measurement is not offered to the public as a service, but is used only for international comparisons and to calibrate

working standards for use in the NBS Electronic Calibration Center.

Reference : M. C. Selby and L. F. Behrent, A bolometer bridge for

standardizing radio-frequency voltmeter s, J. Res. NBS, _44, 15 (1950).

Personnel: M. C. Selby

21-1
RF Voltage (cw) in Coaxial Systems

THERMAL VOLTAGE CONVERTERS at frequencies 30 kHz - 100 MHz

At frequencies below 100 MHz the uncertainties involved in using

thermal voltage converters (TVC's) to compare directly dc and ac voltage, without calibration of the converter on a bridge, have been shown

by Hermach and Williams to be generally less than the bridge uncertainties (See p. 2 1). The most important error in this direct procedure is

the ac-dc substitution error, which has been investigated theoretically

by Hermach and Williams (see Reference p. 21-3). They checked their

theoretical results by making measurements of the ac-dc difference on

the bolometer bridge at frequencies up to 400 MHz, and found satisfactory agreement. In particular, the theory was verified at frequencies

above 100 MHz, where the ac-dc substitution error is greatest and the

bridge uncertainties are less than that error. On the basis of this

verification of the theory, the converters are used as devices (working

standards) to compare ac voltages to dc standards without the use of a bridge. The uncertainty in the TVC as a working standard is taken to be

just the substitution error, as follows:

Frequency

(MHz)

1 3, 10

30

100

Uncertainty

(%)

0. 05

0. 1 0. 2

1.

21-2
RF Voltage (cw) in Coaxial Systems

DIRECT COMPARISON of customer voltmeters with NBS working

standard TVC's:

Bias Uncertainties: In addition to the substitution error considered on

page 21-2, other possible sources of error in an actual comparison of ac voltage with dc are:

Measurement of the dc voltage

Mismatch

Determination of the reference plane

It is felt that these errors are negligible with respect to the uncertainty

of the working standard at frequencies up to 100 MHz, and that they add

between two and four percent to the uncertainties of the working standard

at frequencies between 300 and 1000 MHz.

Random Errors: Negligible

Total Uncertainty:

Frequency

(MHz)

13, 10

30

100

300, 400

500

700, 1000

Uncertainty quoted customer: Same as Total Uncertainty above.

Notes: None

References: F. L. Hermach and E. S. Williams, Thermal voltage converters for accurate voltage measurements to 30 megacycles per second,

Trans. AIEE, Communication and Electronics, No. 49, 200 (July 1960).

M. C. Selby and L . F. Behrent, A bolometer bridge for standardizing

radio frequency voltmeters, J. Res. NBS, 44, 15(1950).

M. C. Selby, Voltage measurement at high and microwave frequencies

in coaxial systems, Proc. IEEE, 5_5, 877 (1967).

Personnel: M. C. Selby, F. X. Ries

21-3

Uncertainty

(%)

0.05

0. 1 0.2

13

5

7
RF MICROVOLTAGE

I - 100 Microvolts, 50 kHz - 500 MHz

100-100,000 Microvolts, 50 kHz -900 MHz

Working Standard

Micropotentiometer

(0.1 V)

|% ( 50kHz - 500 MHz)

5% (700- 1000 MHz)

Working Standard

Micropotentiometer

(0.1 V)

Set of 10 Working Standard

Micropotentiometer

Set of 10 Working Standard

Micropotentiometers

Calibrated Customer

Micropotentiometer

Each Set of 10 Working Standards is Intercompared by Two

Different Techniques as an Internal Check .

22
RF Mic rovoltage

1 - 100 Microvolts; 50 kHz - 500 MHz

100 - 100, 000 Microvolts; 50 kHz - 900 MHz

MICROPOTENTIOMETER CALIBRATION:

Bias Uncertainties:

Uncertainty of the standard (thermal voltage converter)

dc voltage measurement

dc current measurement

attenuation measurement

RF leakage

ground currents (dc)

transfer instrument (RF receiver) sensitivity

determination of voltage reference plane

The largest of these is the uncertainty of the thermal voltage converter,

Random Errors : Negligible

Total Uncertainty:

Frequency Voltage Range Uncertainty

MHz microvolts %

0. 05 - 300 1-100 5 300 - 500 1 - 100 10

0. 05-10 100 - 100, 000 2

10 - 300 100 - 100, 000 3

300 - 900 100 - 100, 000 5

Uncertainty quoted customer: Same as Total Uncertainty, above.

Notes : None

Reference: M. C. Selby, Accurate radio -frequency microvoltages : Trans. AIEE, Communication and Electronics, No. 6, 158-164

(May 1953).

Personnel: M. C. Selby

F. X. Ries

22-1
PULSE VOLTAGE

5 - IOOO Volts

Pulse Length : > 10 Nanoseconds

Known Pulse

Voltage and

Cali bra ted Generator

1%

Cal ibrated

Voltmeter

23
Pulse Voltage

5 - 1000 Volts

Pulse Duration; <1 Nanoseconds

SLIDE BACK VOLTMETER METHOD:

Bias Uncertainties:

Thermal effects 10 mV

Detector null sensitivity 1 mV

dc voltage 0. 05 %

Random Errors: 0. 1 %

Total Uncertainty: 0. 15%±20mV

Uncertainty quoted customer: 1%

Notes: This measurement is made only for pulses longer than 10 nanoseconds.

Measurement agreement between this slideback voltmeter method

and the standard pulse generator method is 0. 3 %. See page 23-2.

Referenc e: A.. R. Ondrejka and P. A. Hudson, Measurement standards

for low and medium peak-pulse voltages, J. Res. NBS, 7 PC , 13 (1966).

Personnel: P. A. Hudson

P. A. Simpson

23-1
Pulse Voltage

STANDARD PULSE GENERATOR (ZENER DIODE) SYSTEM:

Bias Uncertainties:

Thermal effects 0.1 %

10% uncertainty in input pulse voltage 0. 1 dc voltage 0.05

Random Errors: negligible

Total Uncertainty: 0.2 5%

Uncertainty quoted customer: 1%

Notes: This measurement is made only for pulses longer than 10

nanoseconds

.

The 10% uncertainty in input pulse voltage can be either an amplitude

variation of the flat top of an individual pulse or an amplitude modulation

in a series of pulses, or a combination of both.

Measurement agreement between this standard pulse generator system

and the slideback voltmeter system is 0.3%. Seepage 23-1.

Reference: A. R. Ondrejka and P. A. Hudson, Measurement standards

for low and medium peak-pulse voltages, J. Res. NBS, 70C, 13 (1966).

Personnel: P. A. Hudson

P. A. Simpson

23-2
FIELD STRENGTH

30Hz — I GHz

20 -400mV/m

r MAGNETIC FIELDS - LOOP ANTENNAS

"1

3-5%

Known Field at Receiver

20 - 200mV/m

30 Hz - 30 MHz

Standard Field Method

[Normally Used 30Hz — 30 MHz

J r

ELECTRIC FIELDS DIPOLE ANTENNAS

12%

Known Field at Receiver

20 - 400 mV/m

03 — 1 GHz

Standard Antenna Method

Normally Used 30 MHz - I GHz

24
Field Strength

LOOP ANTENNAS, STANDARD FIELD METHOD:

30 Hz - 30 MHz

20 - 200 mV/m

Bias Uncertainties:

Antenna dimensions

Input c urrent

Output voltage (RF)

Effect of earth and other objects

Attenuation measurement

Random Error s: Not reported.

Total Uncertainty: 3% (See Notes)

Uncertainty quo ted customer 3%

No tes: The uncertainty of calibration is determined from two independent measurement methods: (1) the standard-field method, (2) the

standard-antenna method. The standard-field method is used to calibrate loop antennas. The loop is calibrated in terms of a quasi-static

magnetic field and converted to the equivalent electric field based on

free space calibrations.

References : F. M. Greene, NBS field- strength standards and measure'

ments (30 Hz to 1000 MHz), Proc. IEEE, 55, 970 (June 1967).

H. E. Taggart, Field- strengths and RFI standards at the National

Bureau of Standards, 1968 IEEE Electromagnetic Compatability Symposium Record, IEEE 68CIZ-EMC, 149-158.

Personnel : F. M. Greene

H. E. Taggart

24-1
Field Strength

DIPOLE ANTENNAS, STANDARD ANTENNA METHOD:

30 - 1000 MHz

20 - 400 mV/m

Bias Uncertainties:

Antenna dimensions

Output voltage (dc or RF)

Effect of earth and other objects

Attenuation measurements

Random Errors: Not reported.

Total Uncertainty: 12% (See notes)

Uncertainty quoted customer : 12%

Notes: The uncertainty of calibration is determined fromtwo independent measurement methods : (1) the standard-field method, (2) the

standard-antenna method. The standard-antenna method is used to

calibrate dipole antennas. The dipole antenna is calibrated by placing

it in a known field at a specified height above ground.

Re fer ences : F. M. Greene, NBS field- strength standards and measurements (30 Hz to 1000 MHz), Proc. IEEE, 55, 970 (June 1967).

H. E. Taggart, Field-strengths and RFI standards at the National

Bureau of Standards, 1968 IEEE Electromagnetic Compatability

Symposium Record, IEEE 68CIZ-EMC, 149-158.

Personnel : F. M. Greene

H. E. Taggart

24-2
FIELD STRENGTH METER

30 Hz- 1GHz

( 20 - 400mV/m)

3 -12 %

Electric Field Strength

3 - 13 %

Calibrated Receiver

t>

o

3-18 %

Calibrated Field Strength Meter

3-12 %

Calibrated Antenna

25
Field Strength Meter

30 Hz - 1 GHz

Z0 - 4 00 mV/m

RECEIVER CALIBRATION: (See Notes)

Bias Uncertainties:

Voltage measurement 30 Hz - 100 MHz 3%

100 - 500 MHz 5%

500 - 900 MHz 7%

Calibration of attenuators and 30 Hz - 400 MHz 0. ldB + 0. 03dB/ 1 OdB

overall linearity of receiver 400- 1000 MHz 0. ldB + 0. 05dB/ 1 OdB

Random Er r ors : Not reported.

Total Uncertainty: 3% + 0. ldB + 0.03dB/10dB to

7% + 0. ldB + 0. 05dB/10dB

Uncertainty quoted custome r: 3 Hz -100 MHz 5%

100 - 500 MHz 7%

500 - 1000 MHz 10%

Notes: As shown on page 2 5, a field strength meter consisting of an

antenna and a receiver (which itself consists of a detector, internal

attenuators and a voltmeter) can be calibrated as a unit (the "switch"

is shown in that position), or the receiver and the antenna can be calibrated separately (the other "switch" position). When calibrated as a

unit, the uncertainties are those as given on pages 24-1 and 24-2. When

calibrated separately, the uncertainties are as given on pages 2 5-1 and

25-2.

Referenc e : None

Personnel : F. M. Greene

H. E, Taegart

25-1
Antennas

ANTENNA CALIBRATION:

Loop antennas: 30 Hz - 30 MHz

Dipole antennas: 30 - 1000 MHz

Bias Uncertainties: See Notes.

Random Err ors: Not reported.

Total Uncertainty: Loop antennas, 3%; dipole antennas, 12%.

Uncertainty quoted customer: Loop antennas, 3%; dipole antennas, 12%.

Notes : As shown on page 25 the calibration of an antenna by itself is

done by placing the antenna in a known field, terminating it in a known

impedance, and measuring its output voltage. The total uncertainty is

taken to be equal to that of the uncertainty in the field itself, which is

obtained as on pages 24, 24-1, and 24-2.

References : F. M. Greene, NBS field- strength standards and measurements (30 Hz to 1000 MHz), Proc. IEEE, 55, 970 (June 1967).

H. E. Taggart, Field-strengths and RFI standards at the National

Bureau of Standards, 1968 IEEE Electromagnetic Compatability

Symposium Record, IEEE 68CIZ-EMC, 149-158.

Personnel : F. M. Greene

H. E. Taggart

25-2
ATTENUATION: COAXIAL SYSTEMS

10 - 18,000 MHz

- 140 dB

0.002 dB/IO dB to 0.01 dB /I0 dB

1 Reference

Standard Piston Attenuators 10,30,60, 100MHz

0.005 dB/IO dB

30MHz Working

Standard Attenuator

0.005 to 0.23 dB

Calibrated Attenuators 10,30,60,100 MHz

0.03 to 0.15 dB

Calibrated Attenuators db <A < 50db

100- 18,000 MHz

0.15 to 0.36 dB

Calibrated Attenuators 50 db <A <80db

100- 18,000 MHz

26
Attenuation: Coaxial Systems

PISTON ATTENUATION:

10, 30, 60, 100 MHz

- 140 dB

Bias Uncertainties:

Coaxial waveguide diameter 0. 0003dB/ 1 OdB

Linear displacement of receiving coil 0. OOldB / 1 OdB- 0. OldB/lOdB

Velocity of electromagnetic waves in

medium inside guide negligible

RF conductivity of guide 0. 00026dB/10dB

RF permeability of guide negligible

Random Errors: negligible

Total Uncertainty: 0. 002dB/10dB- 0. OldB/ 10dB

Uncertainty quoted customer: See Notes.

Notes : Lower limits of these measurements are not available to

c ustomers,but are used only to establish the uncertainty in the National

Bureau of Standards reference standard piston attenuators.

Referenc e : C. M. Allred and C. C. Cook, A precision RF attenuation

calibration system, IRE Trans. Instr. 1-9, 268 (I960).

Personnel: R. T. Adair

26-1
Attenuation: Coaxial Systems

DUAL-CHANNEL RF NULL SYSTEM :

10, 30, 60, 100 MHz

- 140dB

Bias Uncertainties:

Reference standard piston attenuator 0. 002dB/ 1 OdB- 0. OldB/ 1 OdB

Mismatch errors O.OOldB/lOdB

Leakage O.OOldB/lOdB

Random Errors: See Notes. 0. 001 - 0. 06dB

Total Uncertainty: 0.005 - 0.23dB

Uncertainty quoted customer : Uncertainty is estimated for each individual

case and those estimates are reported directly to the customer.

Notes : The random errors are reported to the customer as 3 times the

standard error, which is defined on the calibration report. Typical

standard errors range from about 0. OOldB at low attenuations up to

about 0. 06dB at high attenuations.

Explicit numbers for mismatch errors and leakage errors are estimated

for each individual case.

The maximum range of the standard piston attenuators is 140dB at

30 MHz and lOOdB at 10, 60, and 100 MHz.

The numbers quoted for bias uncertainties are typical values, and may

not apply to a particular calibration.

R eferenc e: C. M. Allred and C. C. Cook, A precision RF attenuation

calibration system, IRE Trans. Instr. , 1-9, 269 (I960).

Personnel: R. T. Adair

26-2
Attenuation: Coaxial Systems

SINGLE-CHANNEL IF NULL SYSTEM :

100 - 18, 000 MHz

- 50dB

Bias Uncertainties:

Mismatch errors O.OldB/lOdB

Mixer non-linearity 0.005dB/10dB

Noise, as a systematic error 0.005dB/10dB

Leakage 0.005dB/10dB

Working standard piston attenuator

uncertainty 0.005dB/10dB

Random Errors: See Notes.

Total Uncertainty: 0. 03 - 0. 15dB

Uncertainty quoted customer: Reported as estimated in each individual

case.

Notes : The random errors include such effects as connector precision,

generator and detector fluctuations, and noise or instability in the

unknown attenuator. They are reported to the customer as 3 times the

standard error, with a sample size usually 6, giving about a 96%

confidence limit. These random errors are generally negligible.

Explicit numerical entries for the bias uncertainties are estimated in

each individual case.

Reference : David H. Russell, An unmodulated twin-channel microwave

measurement system, ISA Trans., 4, 162 (1965).

Personnel: R. T. Adair

26-3
Attenuation: Coaxial Systems

DUAL-CHANNEL IF NULL SYSTEM:

100 - 18, 000 MHz

50 - 80dB

Bias Uncertainties : Mismatch errors 0. OldB/ 1 OdB- 0. 02dB/ 1 OdB

Mixer non-linearity 0. 005dB/10dB- 0. OldB/lOdB

Noise, as a systematic error 0.005dB/10dB

Leakage 0.005dB/10dB

Working standard piston attenuator 0.005dB/10dB

Random Errors: See Notes, page 26-3.

Total Uncertainty: 0. 15 - 0. 36dB

Uncertainty quoted c ustomer: Reported as estimated in each individual

case.

Notes: Explicit numerical entries for the bias uncertainties are estimated

in each individual case.

References : D. Russell and W. Larson, RF attenuation, Proc. IEEE,

55, 942 (1967).

B. O. Weinschel, G. U. Sorger, and A. L. Hedrich, Relative voltmeter

for VHF/UHF signal generator attenuator calibration, IRE Trans. Instr. , 1-8, 22 (1959).

A. L. Hedrich, B. O. Weinschel, G. U. Sorger, and S. J. Raff, Calibration of signal generator output voltage in the range of 100 to 1000

megacycles, IRE Trans. Instr. , 1-J_, 275 (1958).

Personnel: R. T. Adair

26-4
ATTENUATION : WAVEGUIDE SYSTEMS

1.7 - 40 GHz - 50 dB

0.005 dB/lO dB

30 MHz

Working Standard

Attenuator

0.1 dB/io ( 1.7 -2.6GHz)

0.05dB/lO( 2.6-26GHZ ) 0.1 dB/lO (26-40 GHz ) >

Calibrated Attenuators < A < 50 dB

0.005 dB/IOdB

Calibrated Attenuators

8.2 - 18 GHz

< A < 15 dB

27
Attenuation: Waveguide Systems

1.7-40 GHz

- 50dB

PISTON ATTENUATOR : See page 26-1

SINGLE-CHANNEL IF SYSTEM :

Bias Uncertainties:

Random Errors : } See Error Flow Diagram, page 27-2

Total Uncertainty:

Uncertainty quoted customer:

0. ldB/lOdB; 1.7 - 2. 6 GHz

0.05dB/10dB; 2. 6 - 26 GHz

0. ldB/lOdB; 26 - 40 GHz

Notes : None

Reference : R. E. Larson, Microwave measurements in the NBS

Electronic Calibration Center, Proc. IEE (London), 109 , part B,

suppl. 23, 644 (1962).

Personnel: W. Larson

27-1
IF ATTENUATION CALIBRATION SYSTEM

ERROR FLOW DIAGRAM

FREQUENCY 1.7 -40 GHz WR 430 WR 28

ESTIMATED

RANDOM ERRORS

(INSERTION LOSS)

I 1

ATTENUATION DIFFERE nce]

ESTIMATED

SYSTEMATIC ERRORS

CONNECT

DISCONNECT

I

L

3 Sigma 0.2

J

TOTAL TOLERANCE ALLOWED

3 Sigma

DIAL SETTING

dB ERROR

10 0.009

20 0.014

30 0.022

40 0.037

50 0.059

INSERTION

POINT

INSTABILITY

OF SIGNAL ± 0.004 dB

ATTENUATOR

RESETTABILITY

< r

DIAL SETTING

dB

ERROR

10 0.002

20 0.005

30 0.008 . ' < 40 0.0 15 50 0.025

OPERATOR

PERFORMANCE

DIAL SETTING

dB

ERROR

'

1 0.00 3 20 0.005

30 0.01 40 0.018

50 0.030

RANDOM ERRORS

CRYSTAL

MIXER

(WR 2 34 - - - - \U R 28)

MISMATCH

LINE 1.02 VSWR

ATTENUATOR VSWR

1.05 1. 10 1.15 1.20 0.005 0.008 0.013 O.OI7dB

NON LINEARITY

0.005 dB

NOISE

40 dB 50dB

0.004 0.04dB

RF LEAKAGE

30dB

.003 40.009 50.030 60.090 dB

LOADING

EFFECTS

O.OOIdB

MODE

PURITY

0.001 dB

1 1

' i

r * 30 MHz STANDARD

i ,

i

DIMENSIONAL

TOLERANCE

0.002 dB/INCH

SKIN DEPTH

CORRECTION

0.0015 dB

TOTAL SYSTEMATIC ERRORS

DIAL SETTING ATTEN. VSWR

1.05 1. 10 1. 15 1.20

10 O.OI5dB 0.018 0.023 0.027

20 0.015 0.018 0.023 0.027 30 0.018 0.021 0.026 0.030 40 0.028 0.030 0.0 36 0.040 50 0.085 0.088 0.093 0.097

TO CUSTOMER

27-2
Attenuation: Waveguide Systems

MODULATED SUBCARRIER TECHNIQUE :

Bias Uncertainties:

R andom Er r ors : ) See Error Flow Diagram, page 27-4

Total Uncertainty:

Uncertainty quoted custome r: 0. 005dB/ 1 OdB; 8.2- 18.0GHz

Notes : none

Reference : G. E. Schafer and R. R. Bowman, A modulated subcarrier

technique of measuring microwave attenuation, Proc. IEE (London), 1 09 , part B, suppl. 23, 783 (1962).

Personnel: W. Larson

27-3
ATTENUATION : WAVEGUIDE SYSTEMS

ERROR FLOW CHART FOR MODULATED SUBCARRIER

MODULATION INDEX

DEVIATION 0.0002 dB

INSERTION POINT

0.0012

MISMATCH

0.001 dB

V

PHASE SHIFTER

ADJUSTMENT = 0.0004 dB

R F LEAKAGE

0.0003 dB

CRYSTAL MIXER

0.0021

FREQUENCY STABILITY

0.0001 dB

CRYSTAL NON-LINEARITY

0.0001 dB

' AUDIO STANDARD

0.0001 dB

i

NULL INDICATOR

0.0025

SYSTEM DRIFT

0.0001 dB

AUDIO REFERENCE

AMPLITUDE 0.0002 dB

\ '

TO CUSTOMER

± 0.005 dB

OPERATOR ANOMALY

0.0005

ATTENUATOR ANOMALY

0.002 dB

I

27-4
PHASE SHIFT

IN COAXIAL PHASE SHIFTERS

30- 12,400 MHz

0- 360 Degrees

0.016°- 0.068°

Standard

Trombone"

Phase Shifters

30° Range

30 a 100 MHz

0.05°-0.2°

Working Standard

360° Range

30 MHz

0.05°-0.2°

Calibrated

Phase Shifters

30 8 100 MHz

0.5°

C a I ibrated

Phase Shifters

100- 12,400 MHz

Z8
Phase Shift in Coaxial Two-Ports

30 and 100 MHz

0. 05 - 360 Degrees

DUAL -CHANNEL RF COMPARISONS:

Bias Uncertainties:

Mechanical stability and length

measurement in trombone

phase shifter 0. 004 - 0. 048 degree (30 MHz)

0. 012 - 0. 144 (100 MHz)

Mismatch of trombone 0. 012

Phase shift in standard attenuator 0. 01

Resolution in auxilary phase shifter 0. 02 - 0. 13

Random Errors: negligible

Total Uncertainty: 0. 046 - 0. 2 degree (30 MHz)

0. 054 - 0. 208 degree (100 MHz)

Uncertainty quoted customer: Reported as estimated for each individual

case.

Notes: Where there is a range of uncertainty in the list above, the uncertainty is a function of the phase shift in the coaxial two -port.

Reference : David H. Russell, An unmodulated twin-channel microwave

measurement system, ISA Trans., 4, 162 (1965).

Personnel: R. T. Adair

28-1
Phase Shift in Coaxial Phase Shifters

30 - 12,400 MHz

= 360 degrees

DUAL-CHANNEL RF COMPARISONS:

Bias Uncertainties:

Mechanical stability and length

measurement in trombone

phase shifter 0. 004 - 0. 048 degree (30 MHz)

0. 012 - 0. 144 (100 MHz)

Mismatch of trombone 0. 012

Phase shift in standard attenuator 0.01

Resolution in auxiliary phase shifter 0.02 - 0. 13

Random Errors: negligible

Total Uncertainty: 0.05 - 0. 2 degree (30 MHz)

o 05 - 0.21 degree (100 MHz)

Uncertainty quoted customer: Reported as estimated for each individual

case.

Notes : Where there is a range of uncertainty in the list above, the

uncertainty is a function of the phase shift in the coaxial phase shifter.

Reference : David H. Russell, An unmodulated twin-channel microwave

measurement system, ISA Trans., _4, 162 (1965).

Personnel: R. T. Adair

28-2
Phase Shift in Coaxial Phase Shifters

DUAL- CHANNEL IF UNMODULATED COMPARISON SYSTEM:

100 - 18, 000 MHz

- 360 degrees

Bias Uncertainties:

30 MHz working standard (resolver) 0.2 degree

Mismatch of unknown phase shifter 0. 05

Mixer non-linearity (See Notes)

Resolution (null sensitivity) 0. 1

Random Errors: negligible

Total Uncertainty: <0.35 degree

Uncertainty quoted customer: 0.5 degree.

No tes : The mixer non-linearity error is determined separately for

each calibration.

Reference : David H. Russell, An unmodulated twin-channel microwave

measurement system, ISA Trans., 4, 162 (1965).

Personnel: R. T. Adair

28-3
PHASE SHIFT

IN WAVEGUIDE PHASE SHIFTERS

WR 62 : 12.4 -18.0 GHz

WR 90 : 8.20 -12.4 GHz

WR 137 : 5.85- 8.20 GHz

0-720 Degrees

0.0'58 -Q.\\A <

Standard

Phase Shifters

Operating at Frequency

of Microwave

Signal Source,

720° Range

0.1 .0°

Calibrated

Phase Shifters

5.85 - 18.0 GHz

29
PHASE SHIFT IN WAVEGUIDE PHASE SHIFTERS

ERROR FLOW DIAGRAM

FREQUENCY 5.85 - 18.0 GHz WR62, WR90and WR 137

MICROWAVE

FREQUENCY

INSTABILITY

0.001

PHASE SHIFT

RESETTABILITY

0.020'

"">

OPERATOR

PERFORMANCE

GHz

6.0 18.0 0.03° 0.09°

RANDOM ERROR

TOTAL TOLERANCE ALLOWED

3 Sigma

MISMATCH

INSERTION

POINT

LINE\

VSWR

I.I 1.2 1.3 1.4

1.01 .06°-^-'

Ji-l^_k^"_2^9!-j

DIMENSIONAL

(90°) GHz K n IQ n

50/i" Aa 0.002° 0.007°

t STANDARD

MICROWAVE

PHASE SHIFTER

CHANGE OF

DIELECTRIC

CONSTANTOFAIR

'

i ,

0.052°

(90°) TUNING

ERROR

0.041° - t.,

0.011° - t2

1 MISMATCH ERROR TOTAL SYSTEMATIC ERROR

Det. 6.0 GHZ18.0 2 0.11° 0.29°

5 0.09° 0.22°

II 0.08° 0.19°

±

\s.

LINE\

VSWR

1.10 1.20 1.30 1.40

1.01 .060° .110° .150° .195°

1.02 .120° .210° .300° .400°

1.05 .320° .560° .810° .960°

1.10 .780° 1.25° 1.60° 2.00°

, GHz

6.0 18.0 90° ! 0.055° i 0.056°

180° 0.079° 0.081 ° 360° 0.01 1 °

j 0.01 3°

TOTAL UNCERTAINTY IS ARITHMETICAL SUM^ (LIKE SIGNS) OF THE

~" RANDOM ERROR, AND TOTAL SYSTEMATIC ERROR

TO CUSTOMER

29-1
Phase Shift in Waveguide Phase Shifters

5. 85 - 18 GHz

- 720 degrees

Bias Uncertainties

Random Errors : ) See Error Flow Diagram, page 28-1

Total Uncertainty:

Uncertainty quote d customer: Same as Total Uncertainty.

Notes : The VSWR of the phase shifter must be less than 1. 5. Resolution of the phase shifter should be 0. 5° or better.

Reference: D. A. Ellerbruch, Evaluation of a microwave phase

measurement system, J. Res. NBS, 69C, 55 (1965).

Personnel: W. Larson

E. D. Hall

29-2
REFLECTION COEFFICIENT MAGNITUDE OF

WAVEGUIDE DEVICES

WR 42 : 18.0 - 26.5 GHz

WR 62 : 12.4 - 18.0

WR 90 : 8.2 - 12.4

WR 112 : 7.05 - 10.0

WR 137 : 5.85 - 8.2

WR 187 : 3.95 - 5.85

WR 284 : 2.6 - 3.95

0.024 < |T| < 0.2

Power Level : 0.0I mW

A|r!< 3.2*icr 5

(i + 5lrl)

Ideal Ref lectometer

Alrl

in

< 3 x I0"4

Working Standard

of Reflection Coefficien

Magnitude

a |r|<2xicr4

(i -ho |r|)

>

Reflection Coefficient Magnitude

in

of Customer Standard

r|

A |r| < 3.5 x icr4

Known Variable Attenuator

30
Reflection Coefficient Magnitude of Waveguide Devices

GHz

Bias Uncertainties:

Random Errors

WR 42 18 • 26. 5

WR 62 12. 4 - 18.

WR 90 8. 2 - 12. 4

WR 112 7. 05 - 10.

WR 137 5 85 - 8 2

WR 187 3. 95 5. 85

WR 284 2 6 - 3. 95

Power Level: 0.01 - 4 mW

See Error Flow Diagrams, pages 30-2 and 30-3

Total Uncertainty:

Uncertainty (typical) quoted customer: r > 0.024,

A I r| = 2 x 10" (1 + 6 |r|)

|r|< 0.024,

A I rl = 2 x 10" (1 + lo|r|)

Notes: The uncertainties due to the precision waveguide section (see

error flow diagrams, pages 30-2 and 30-3) are as follows:

Waveguide Uncertainty in j T | WR 284

WR 187

WR 137

WR 112

WR 90

WR 62

WR 42 (square flange)

WR 42 (round flange)

< 0.0001

< 0.0001

<0.0001

<0.0001

<0. 00015

<0.0001

<0.0004

<0.0003

Reference: Wilbur J. Anson, A guide to the use of the modified reflectom<

eter technique of VSWR measurement, J. Res. NBS, 65C, 217 (1961).

Personnel: B. C. Yates

30-1
CO

LU

CD *

CO

CD

CD

CD

CSJ

V

o o fTS

1

% ±1 A

«• o » U~2 < 2

X i— >* CO CS

a; cnj o O.I ro

"* ' +1 +1

1 r en

LU CO --^

I

U_l

;^>~

1 4)

tj, CNJ — *— to

U_l = +1 —- l_l_ 1— + uu

1 i —

-—*> *

l_ X i

SION ION

i f^ — i

O w o f?. « >-U ro — U-J uj

OC — x °= CO

ro

Q_ + <=»2f ujt s co

ae i rr as.

i O JS

>—1 <=>

OWER INSTA

RAF ER

Q_

30

MHz

STANDARD

±

0.006

dB

v

ATTENUATION

MEASUREMENT

±0.012

JB

OR

±l.4i-l(T

5

|r|

i i

CRYSTAL LINEARITY

±0.006JB

«u

c

a>

w, v>o2

0)

a>

0) a>

a> a>

</) </> * *

*

30-2
en

CO

Ll_l

CD

co

*

CD

u~s

+1

CD

CD

CD

CVJ

CD

Al

a ~—

Q= U

Stae <o

«c ~* H- ** CO CD

-<l* +1

CO ^~. OS

ce i —

+1 —

+

CD

CD

>- » —

tZ oil

i= **

• Wpri -

+1 +

CO 2

5

s to

ce:

C_5

qc:

CO

U I C=> % CO

30

MHz

STANDARD ±0.003dB

w

ATTENUATION MEASUREMENT

±

0.006 dB

OR

±7.0xl0"

4

|r|

i i

CRYSTAL LINEARITY

±0.003dB

CDO

c

a> W) k. 0) CD *— V- o CD 2 cr

<D CD

a> CD CO CO * *

*

30-3
DISTRIBUTED PARAMETERS IN COAXIAL SYSTEMS

0.5 - 8 GHz

Standard

Slotted

Line

0.1 - I %( VSWR)

0.1 °- 1.0° (Phase Angle)

VSWR and

Phase Angle

of Load

I < VSWR < 100

0.00025 or I % of I T | Reflection

Coefficient

(Magnitude Only)

31
Distributed Parameters in Coaxial Systems

0. 5 - 8 GHz

SLOTTED LINE MEASUREMENTS :

500 MHz - 8 GHz

1 < VSWR < 100

Bias Uncertainties:

Residual VSWR

(a) Imperfect transition from connector to slotted line

(b) Variation in characteristic impedance

(c) Slot effects

Probe Effects

(a) Variation of probe coupling with probe position

(b) Probe loading of the slotted line

Line losses

Detector nonlinearity

Determination of the position of a voltage minimum

Power and frequency instability

Random Errors : Negligible

Total Uncertainty:

0. 1 - 1.0% for 1 < (VSWR) < 4

0. 1 - 1 degree (phase angle)

Uncertainty quoted customer: As above.

Notes : Page 31-2 gives some details of the error sources. Further

details are available fromR. L. Jesch (below).

Uncertainty figures assume precision 14mm coaxial connectors. Uncertainties for other connectors and larger VSWR's will, in most cases,

be larger.

Reference : R. L. Jesch and R. M. Jickling, Impedance measurements in

coaxial waveguide systems, Proc. IEEE, 55, 912 (June 1967).

Personnel: R. L. Jesch

31-1
N * s

h--

-J Z. < 00

Q

LlJ Q.

0_O

UJCOQ

a:< X<ou££ 2 £

CO<a

UJ

0. 3

CO<

UJ

CO

orO

hCJUJ

uO

cc «2 O O

o: uj

UJ

or

q. o

hQL3

CO

UJ3o < z Q

UJ

uj a: io

UJ

UJ

UJ

or3

CO<

UJ

or<3O

UJ

oro x<oo

oro

U_ < 2

-5

X >- 5 < o < O -I or o o_ o ^ < E uj

°|uj £-? Q _ Ija

UJ

CO

31-2
Distributed Parameters in Coaxial Systems

1 - 4 GHz

COAXIAL REFLECTOMETER MEASUREMENTS:

1 - 4 GHz

o < | r | < i

Bias Uncertainties:

Tuning errors

Detector errors

Precision air-line section

Power and frequency instability

Random Errors : Negligible

Total Uncertainty:

for < |r| < 0.025:& |r| < 0. 00025

for 0.025 < [r| < i: a |r| < i% jr|

Uncertainty quoted customer: As above

Notes : In other than exacting standards work, or unless specially

requested, this measurement is rarely done for customers. Satisfactory

results may be obtained at a much lower cost by the slotted-line

technique.

Reference : W. E. Little and J. P. Wakefield, Measurement of Precision coaxial connectors using reflectometer techniques, IEEE

International Conv. Rec, pt. 11, 89-97, March 1965.

Personnel: R. J. Jesch

31-3
HIGH FREQUENCY IMMITTANCE

30 KHz - 300 MHz

C : I0

-12 - I0"7 F L : I0

-8 - I H

R : 0.1 - I0 6

ft Effective Resonating Capacitonce (Ce) : 35 x I0~l7 -450x I0" 2 F

Effective Quality Factor (Qe) : 90-700

Precision Coax Lines

Thompson- Lampard

Capacitance Standards

Standard Resistors

R < l0 9/cu IO"'<L < 10

i<rl4 < c < icr 9 (Three-Terminal )

C < 50x ICT 12

( Two-Terminal)

35 x IO"

l2 ^Ce S 450 x I0

-12 and 90 < Qe < 700

U) ' Angular Frequency

32
High Frequency Immittance

30 kHz - 300 MHz

-12 -7

Capacitance: 10 - 10 F

Inductance: 10 - 1 H

Resistance: 0. 1 -10ft

Bias Uncertainties:

Null detection

Generator frequency stability

Mechanical errors (e.g., gears)

Connec tors

Random Errors : 0. 01 to 0. 05% (see Notes).

Total Uncertainty:

Capacitance (2 terminal) 0. 1 - 0. 5%

Capacitance (3 terminal, see Notes) 0.01 - 2%

Inductance 0. 1 - 20%

Resistance 0. 1 - 10%

Uncertainty quoted customer: Quoted as estimated for each individual

case.

Notes : The 3-terminal capacitance measurements are made only in the

frequency range 100 kHz - 1 MHz, and in the capacitance range 0. 01 - 1000 pF.

A more detailed listing of the uncertainties as a function of frequency

and value of the immittance is available from R. N. Jones or R. E.

Nelson (below).

The distribution of random errors depends strongly on the nature of the

device being calibrated. In the field of immittance there is little uniformity in the transfer standards used throughout the industry. Thus,

it is not generally possible for NBS to give information on random errors

based on a large amount of experience with a particular type of transfer

standard.

The uncertainties are stated on the basis of the use of precision connectors, which are not always used on devices NBS is asked to calibrate.

Where precision connectors are not used the errors can be considerably

larger than those quoted.

The uncertainties listed under bias uncertainties above apply to all

bridge measurements shown on page 32.

32-1
The chart on page 32 shows the most commonly used sequence of measurements. The procedure varies somewhat for specific frequencies

and magnitudes.

Reference : L. F. Huntley and R. N. Jones, Lumped parameter impedance measurements, Proc. IEEE 55 , 900 (1967).

Personnel : R. N. Jones

R. E. Nelson

32-2
Quality Factor and Effective Resonating Capacitance

50 kHz - 45 MHz

Ranges: Effective Quality Factor (Q ): 100 - 700

Effective Resonating Capacitance (C ): 30 - 500 pF

e Bias Uncertainties:

Inductance and resistance measurements using NBS standards

Connector errors

Random Er rors : See Notes

Effective resonating capacitance (C ) 0. 15 - 0.5%

Effective quality factor (Q ) 0. 8 - 2.3%

e Total Uncertainty: See Notes

Uncertainty quoted customer: Same as Random Errors. See Notes.

Notes : The Q standards calibrated by NBS are used largely to establish

measurement agreement, with less concern with the absolute accuracy

of the measurement of quality factor or effective resonating capacitance.

The bias uncertainties are believed to be about the same as the random

errors stated above, except for Q above 5 MHz, where difficulties due

to connectors and measurement of small resistances become more

severe.

As in the immittance standards calibrated by NBS, the uncertainties

associated with connectors other than precision connectors are serious.

A more detailed display of the uncertainties as a function of frequency

and magnitude of the parameter being measured is available from

R. N. Jones or R. E. Nelson (below).

Refer ence: R. N. Jones, Standards for the calibration of Q-meters,

50 kHz to~45 MHz, J. Res. NBS, ^8^ 243 (1964).

Personnel : R. N. Jones

R. E. Nelson

32-3
LARGE

COMPLEX RELATIVE DIELECTRIC PERMITTIVITY

30 kHz - 100 MHz

Ranges : €' (Real Part) >l

r

2

Frequencies

- < tan 8 (Loss Tangent) < 10^

30 kHz- 100 MHz

Sample

of Known

Geometry

>2% (€')

5% (tan 8) e and tan 8

30 kHz -100 MHz

33
Large

Complex Relative Dielectric Permittivity

PERMITTIMETER MEASUREMENT :

30 kHz - 100 MHz

Range: e' > 10

14 /[f(Hz)] 1,S

o > 10

4/[f (Hz)]

' 5

10" < tan 6 < 10 (see Notes)

Bias Uncertainties : Toroidal sample geometry

Reproducibility of making and breaking magnetic circuit

Immittance measurements on primary winding of permittimeter

Random Errors : Not reported.

Total Uncertainty : t

' : > 2 %

tan 8 : > 5 %

Uncertainty quoted customer : Same as Total Uncertainty.

Notes : The range of tan 5 is approximate. The specified rather

large values of either e' or 8 , to give either displacement or real

currents, is a fundamental requirement.

Reference : R. C. Powell and A. L. Rasmussen, A radio frequency

permittimeter, IRE Trans. Instr. , 1-9, 179(1960).

Personnel : H. E. Bussey

33-1
HIGH FREQUENCY

RELATIVE DIELECTRIC PERMITTIVITY, REAL PART

30kHz- IGHz

Range : I - I0 4

0.4 - 1 %

Real Part of Permittivity

30kHz - 10MHz

0.4.-1 %

50kHz - 250 MHz

0.09 - I GHz

34
High Frequency Relative Dielectric Permittivity, Real Part, f

'

BRIDGE MEASUREMENT :

Capacitor-type sample holder

30 kHz - 10 MHz, 1 < «' < 10 4

Bias Uncertainties:

Capacitance (see Notes) 0.05%

Lead inductance negligible

Fringing capacitance negligible

Sample geometry (see Notes) 0. 5 (10" 2 /t)%

Sample stability including humidity effects negligible

Interaction of real and imaginary parts negligible

Random Errors : not reported

-2

Total Uncertainty : [0.05+0.5(10 /t)]%

Uncertainty quoted customer : 0.4 - 1%

Notes : The capacitance measurement is a change in capacitance, with

and without the sample. The error depends upon the thickness of the

sample and upon t '.

The sample geometry uncertainty depends upon the thickness of the

sample, t, which is approximately 0.1 inch.

Reference : H. E. Bussey, Measurements of RF properties of materials,

a survey, Proc. IEEE, 55, 1046 (June 1967).

Personnel : H. E. Bussey

34-1
High Frequency Relative Dielectric Permittivity, Real Part, e ' Q-METER MEASUREMENT :

Capacitor-type sample holder

I ^ ia4 50 kHz - 250 MHz, 1< e' < 10

Bias Uncertainties :

Capacitance (see Notes) 0.05%

Lead inductance negligible

Fringing capacitance negligible

Sample geometry 0.5 (10 /t)%

Sample stability negligible

Indirection of real and imaginary parts negligible

Random Errors: not reported

-2

Total Uncertainty : [0.05+0.5(10 /t)]%

Uncertainty quoted customer : 0.4 - \°Ji

Notes : The capacitance measurement is a change in capacitance, with

and without the sample. The error depends upon the thickness of the

sample and upon e '.

The sample geometry uncertainty depends upon the thickness of the

sample, t, which is approximately 0.1 inch.

Reference : See page 34-1

Personnel : H. E. Bussey

34-2
High Frequency Relative Dielectric Permittivity, Real Part, e' RE-ENTRANT CAVITY MEASUREMENT :

Capacitive gap in coaxial transmission line

0.09 - 1 GHz, 1 < e" < 10 4

Bias Uncertainties :

Capacitance 0.2 to 0. 5%

Sample geometry, including foil contact 2(10~^/t)%

Fringing fields 0.2%

Random Errors : not quoted

Total Uncertainty: [0 . 4 to . 7 + 2 (10

~ 2

/ t)]%

Uncertainty quoted customer : 1 - 10%

Notes : The sample thickness, t, is approximately 0.05 inch.

Reference : See page 34-1

Personnel : H. E. Bussey

34-3
HIGH FREQUENCY DIELECTRIC LOSS

30kHz - 1GHz

Range : 10-4- |Q3 ( tan S)

Samples

of Known

Geometry

0.00005 or 10%

Loss Tangent

(tanS)

30kHz - 10MHz

0.00005 or 10%

tan 8

50kHz - 250 MHz

0.00005 or 10%

tan 8

0.09 - I GHz

35
High Frequency Dielectric Loss

BRIDGE MEASUREMENTS:

Capacitor-type sample holder

30 kHz - 10 MHz, 10" 4 <tan 5 < 10

Bias Uncertainties :

Sample geometry 0. 5 to 1%

Bridge measurement of conductance 2%

-3

Random Errors: 5 x 10 / tan 5 %

_3

Total Uncertainty : [2. 5 to 3 +5x10 /tan 6]%

Uncertainty quoted customer: 0.00005 or 10%, whichever is larger.

Notes : None

Reference : See page 34-1

Personnel : H. E. Bussey

35-1
High Frequency Dielectric Loss

O-METER MEASUREMENT:

Capacitor -type sample holder

5 kHz - 250 MHz, 10" < tan 6 < 1

Bias Lnc ertainties

:

Geometry of sample 0. 5 to 1%

Q-meter measurement 5%

_3 Random Errors: 5x10 /tan 8 %

Total Uncertainty: '% [_ 5 . 5 to 6- 5x 10 /tan 8 ~\%

Uncertainty quoted customer: 0. 00005 or 10 ro, whichever is larger,

N_ote_s_: By special request, loss tangents as low as 0. 00001 are

measured.

Reference : See page 34-1.

Personnel: H. E. Bussey

35-2
High Frequency Dielectric Loss

RE-ENTRANT CAVITY MEASUREMENT:

Capacitive gap in coaxial transmission line

0.09 - 1 GHz, 10" < tan 8 < 1

Bias Uncertainties:

Attenuation measurement 0. 3%

Sample geometry 1 to 2%

Q measurement, including attenuation errors 2 to 3%

Bias from unknown sources (see Notes) 4x10 /tan 8 %

Random Errors: not quoted

Total Uncertainty: [3 to 5 + 4 x 10~ /tan 5]%

Uncertainty quoted customer: 0.00005 or 10%, whichever is larger.

Notes : There are some bias errors from sources which have not yet

been identified. Their total magnitude is determined by calibration

against samples having known loss tangents.

Reference : See page 34-1.

Personnel: H. E. Bussey

35-3
MICROWAVE

COMPLEX RELATIVE DIELECTRIC PERMITTIVITY

Dielectric Loaded Transmission Lines

0.3 - 8.6 GHz

Range: I - 20 ( Real Part)

v-4 10" -10" ( Loss Tangent)

Load of Known Geometry

Complex Propagation

Constant

,

in Sample

H0.8-2.6% («')

0.0002 or 5% (tan 8)

Complex

Dielectric Permittivity

(e' - je'tanS)

36
Microwave Complex Relative Dielectric Permittivity, Real Part, e' DIELECTRIC LOADED TRANSMISSION LINES:

Slotted line impedance measurements

0. 3 - 8. 6 GHz

Bias Uncertainties

Sample diraensions 0. 5%

Gap errors around sample 0. 2 to 2%

Attenuation measurement negligible

Probe position and wavelength measurements 0. 1%

Random Errors : not reported

Total Uncertainty: 0. 8 to 2. 6%

Uncerta i nty quoted c ustomer: 0. 8 - 2.6%

Notes : The real and imaginary parts of the permittivity are determined

together in this method, as shown by the diagram on page 36. However,

the errors in the real and imaginary parts are not the same, and are

therefore discussed separately on pages 36-1 and 36-2.

Reference: See page 34-1.

Personnel: H. E. Bussey

36-1
Microwave Complex Relative Dielectric Permittivity,

Loss Tangent

DIELECTRIC LOADED TRANSMISSION LINES

Slotted line impedance measurement

0.3 - 8.6 GHz

Bias Uncertainties :

Contribution of magnetic permeability to 1%

Gap errors 0. 2 to 2%

"Law" of crystal 2%

Environment ( see Notes) 0.5%

Random. Errors : not reported

Total Uncertainty : 3.5 to 5. 5%

Uncertainty of tan 8 quoted customer : 0.0002 or 5%, whichever is

larger.

Notes : Errors due to environment include foreign surface conductivity,

temperature effects, etc.

Reference : See page 34-1

Personnel : H. E. Bussey

36-2
MICROWAVE COMPLEX RELATIVE

DIELECTRIC PERMITTIVITY

Transmission Cavities

0.5, I, 3, 6, 9 and 30GHz

Range : 1-100 (Real Part)

I0" 4

- I0"

1 (Loss Tangent)

Load of Known Geometry

5-10%

Dielectric Loss Tangent (S)

Real Part of Permittivity ( e')

37
Microwave Complex Relative Dielectric Permittivity, Real Part, e* TRANSMISSION CAVITIES:

1< e < 100

0.5, 1, 3, 6, 9, and 30 GHz

Bias Uncertainties:

Volume measurements (sample volume and

cavity volume) 0.1 to 0. 2%

Change in length or change in frequency negligible

Misfit of sample in cavity 0.2 to 0. 8%

Random Errors : not quoted

Total Uncertainty: . 3 to 1%

Uncertainty quoted customer : 0.3 - 1%

Notes: A TE mode circular cavity resonator is used at 3, 9, and

30 GHz. Sample may be either a rod or a disk. At 0.5, 1, and 6 GHz

01 k,

other modes are used, and the accuracy is lower than for the TE

modes. Results are based on exact solutions for a rod and disk. "Either

a complex propagation constant may be used when the loss is high, or the

real and imaginary parts may be calculated separately.

Reference : See page 34-1

Personnel : H. E. Bussey

37-1
Microwave Complex Relative Dielectric Permittivity, Loss Tangent

TRANSMISSION CAVITIES:

0. 5, 1, 3, 6, 9 and 30 GHz

Bias Uncertainties:

Attenuation 0. 3%

Q measurement, including attenuation errors 1 to 2%

Gap errors 1%

Environment see Notes

Bias from unknown sources |_4 x. 10" /tan <5J %

Random Errors : not reported

Total Uncertainty: [2.5 to 3.5 I4x 10" /tan 5]%

Uncertainty quoted customer: 5-1 0%

Notes: Environmental errors include foreign surface conductivity,

temperature effects, etc. Their magnitudes are not well known.

There are some bias errors from sources which have not yet been

identified. Their total magnitude is determined by calibration against

samples having known loss tangents.

The transmission coefficient of the cavity is often used to obtain the loss;

see reference below.

Also, see Notes on page 37 - 1 .

Referenc e : H. E. Bussey, Cavity resonator dielectric measurements on

rod samples, 1959 Annual Report, Conference on Electrical Insulation,

National Academy of Sciences, Publication 756 of the National Research

Council.

Personnel: H. E. Bussey

37-2

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entitled, Standardization of Data Elements and Codes

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