IEC 60317-36:1992

SLOVENSKI STANDARD
01-avgust-1995
Terminologija za mikrovalovne naprave
Terminology for microwave apparatus
Terminologie pour appareils à micro-ondes
Ta slovenski standard je istoveten z: IEC 60615
ICS:
01.040.29 Elektrotehnika (Slovarji) Electrical engineering
(Vocabularies)
29.020 Elektrotehnika na splošno Electrical engineering in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEI
NORME
IEC
INTERNATIONALE
INTERNATIONAL
Première édition
STAN DARD
First edition
1978-01
pour appareils à micro-ondes
Terminologie
Terminology for microwave apparatus
© CEI 1978 Droits de reproduction réservés — Copyright - all rights reserved
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— 3 —
CONTENTS
Page
FOREWORD 5
PREFACE 5
Clause
1. General
2. General terms
3. Frequency
4. Immittance
5.
Noise figure
6. Power, attenuation and gain

7. Signals
INTERNATIONAL ELECTROTECHNICAL COMMISSION
TERMINOLOGY FOR MICROWAVE APPARATUS
FOREWORD
1) The formal decisions or agreements of the I E C on technical matters, prepared by Technical Committees on which all the
National Committees having a special interest therein are represented, express, as nearly as possible, an international
consensus of opinion on the subjects dealt with.
They have the form of recommendations for international use and they are accepted by the National Committees in that
2)
sense.
In order to promote international unification, the IEC expresses the wish that all National Committees should adopt the
3)
text of the 1 E C recommendation for their national rules in so far as national conditions will permit. Any divergence
between the IEC recommendation and the corresponding national rules should, as far as possible, be clearly indicated in
the latter.
PREFACE
This standard has been prepared by IEC Technical Committee No. 66, Electronic Measuring
Equipment.
A first draft was discussed at the meeting held in Baden-Baden in 1972. The draft, Document
66(Central Office)20, was submitted to the National Committees for approval under the Six
Months' Rule in September 1975.
The following countries voted explicitly in favour of publication:
Netherlands
Australia
Poland
Belgium
Denmark Spain
Finland Sweden
Turkey
France
Union of Soviet
Germany
Socialist Republics
Hungary
United Kingdom
Italy
Japan United States of America
This standard complements the definitions appearing in Chapter 62 of the International
Electrotechnical Vocabulary: Waveguides, published in 1961. This chapter, incidentally, is under
revision at the time of publication of the present standard.

7 —
TERMINOLOGY FOR MICROWAVE APPARATUS
1. General
1.1 Scope
This standard applies to microwave measuring apparatus and microwave measuring
techniques.
Note. —
The term microwaves is used to signify radio waves in the frequency range from about 1 GHz upwards.
(The low-frequency boundary of the microwave range is usually considered to be where lower-frequency
techniques and lumped circuit elements cannot generally be used efficiently. It is then necessary to apply
distributed line techniques and transmission line theory.)
1.2
Object
To establish the essential definitions related to microwave measuring techniques and
apparatus.
2. General terms
2.1 Anechoic chamber
A space bounded by absorbing wall coating, such that the walls can be considered as being
non-reflective for electromagnetic waves in a stated frequency range.
2.2 Cavity resonator
A space bounded by conductive coating to obtain resonance of a specific mode at a stated
frequency.
2.2.1
Echo box
A tunable cavity resonator used for the purpose of supplying a signal at a particular
frequency to adjust a radar receiver. This signal is available during the "ringing" time of the
resonator, after the transmitter pulse is turned off.
2.3 Circulator
A multiport device in which power to any port is transmitted to the next port according to
a given order of sequence.
Note. —
By reversing the biasing field the order of sequence is reversed. This property may be used to switch
electromagnetic energy.
2.4 Isolator
A passive two-port device having much greater attenuation in one direction of propagation
than in the other.
Note. —
The ratio (usually expressed in decibels) of the power entering the output port and the power delivered to
the input port is called isolation.

— 9 —
2.5
Corner reflector
A reflecting object consisting of two or three mutually intersecting flat conducting surfaces
and functioning by multiple reflection.
Note. Corner reflectors may be dihedral or trihedral. A 90° trihedral reflector may be used as a radar target, since
regardless of exact orientation the incident wave retraces its path.
2.6 Cut-off frequency of a waveguide mode
That frequency below which the propagation constant of a waveguide becomes real for a
specific mode, so that no significant propagation in that mode is possible.
2.7 Cut-off frequency of a waveguide
That frequency below which a travelling wave in the dominant mode cannot be
satisfactorily propagated.
2.8 Electrical length (in units of angle)
(in degrees) is defined as:
For an arbitrary device, the electrical length 1
l âfx(df)ix360
where:
dBr
df = rate of change of the phase difference (with frequency) between input and output of the device
dû0
d f = rate of change of the phase difference (with frequency) between two points in free space separated by one
wavelength
Note. — For devices having an electrical length less than 90°, a simpler definition may be used: the phase difference
(in degrees) between input and output signal of a two-port device at a specific frequency.
2.9 Guided wave
An electromagnetic wave which propagates along or between physical boundaries or
structures.
2.10 Group-delay
The slope of the phase/angular frequency transmission characteristic of a microwave device.
2.11
Gyrator
Non-reciprocal phase-shifter having a differential phase shift of it radians.
Note. — The use of the word gyrator to denote gyromagnetic devices in general is deprecated.
2.12 Waveguide transmission modes
2.12.1 Dominant mode
The mode with the lowest cut-off frequency.

— 11
2.12.2 Transverse electric (T.E. or H) mode
A mode in which the longitudinal component of the electric field is zero at all points and
the longitudinal component of the magnetic field is not zero.
2.12.3 Transverse magnetic (T. M. or E) mode
A mode in which the longitudinal component of the magnetic field is zero at all points and
the longitudinal component of the electric field is not zero.
2.12.4 (T. E. M. or E. H.)
Transverse electromagnetic mode
A mode in which the longitudinal components of both the electric and magnetic fields are
zero at all points.
2.12.5 Hybrid mode
A mode in which both the electric and magnetic fields have longitudinal components.
2.13 Balanced modulator
A modulator in which certain modulation components are suppressed by a balanced
arrangement of elements.
2.14
Linear modulator
A modulator in which, for a given magnitude of carrier, the modulated characteristic of the
output wave bears a substantially linear relation to that of the modulating wave.
2.15
Propagation constant
In a rectilinear uniform transmission line, at any given frequency, the propagation constant
of a unidirectional transmission mode of an electromagnetic field, which is a sinusoidal
function of time at that given frequency, is the logarithmic rate of change with respect to
distance of the complex amplitude of any arbitrary field component at any arbitrary point of
any arbitrary section of the line. The propagation constant is a complex quantity.
2.15.1
Attenuation constant
The real part of the propagation constant (usually expressed in nepers per unit length).
2.15.2 Phase constant
The imaginary part of the propagation constant (usually expressed in radians per unit
length).
2.16
Velocity concepts
2.16.1 Phase velocity of a transmission mode
The ratio between the angular frequency and the phase constant of a given transmission
mode.
— 13 —
2.16.2
Group velocity of a transmission mode
The reciprocal of the rate of change with respect to angular frequency of the phase
constant of a given transmission mode.
The group velocity coincides with the phase velocity if the phase constant is a linear function of the angular
Note. —
frequency.
2.17 Transmission line
A material structure forming a continuous path from one place to another, for directing
the transmission of electromagnetic energy along this path.
2.18 Waveguide
A transmission line comprising a conductive tube which may contain a material dielectric.
2.19 Dielectric waveguide
A transmission line in which the waves are guided by dielectric material without conductive
boundaries.
2.20 Cut-off wavelength
The cut-off wavelength of a waveguide mode is the free space wavelength which
corresponds to the cut-off frequency.
2.21 Waveguide wavelength
The wavelength of a propagation mode of a waveguide is the distance between two
7C. It is equal
transverse planes at which the phases of the same field components differ by 2
therefore to the ratio between the phase velocity and the frequency.
For a waveguide filled with uniform dielectric, the waveguide wavelength is given by the
formula:
^
^ g =
where: /Er 2
c
sr = relative dielectric constant
7 = free space wavelength and
= cut-off wavelength of the given mode in the same air-filled guide
For a waveguide with air dielectric, the wavelength is given by the formula:
^
where:
= free space wavelength and
= cut-off wavelength of the given mode in the same air-filled guide
3. Frequency
3.1 Frequency meter
3.1.1 Digital frequency meter
An instrument in which the measured frequency is indicated in the form of a number
digitally displayed.
— 15 —
3.1.2 Absorption frequency meter (wavemeter)
A cavity, calibrated in frequency and coupled to a transmission line, which, when tuned to
the frequency of the propagating wave, absorbs electromagnetic power from that transmission
line.
3.1.3 (wavemeter)
Transmission frequency meter
A cavity, calibrated in frequency and inserted in a transmission line, which, when tuned to
the frequency of the propagating wave, allows power to pass from the transmission line into
a detector.
3.2 Frequency multiplier
A device for delivering an output wave whose frequency is a multiple of the input
frequency.
3.3 Frequency divider
A device which divides the frequency of a continuous wave signal by an integral number.
3.4 Spectrum analyser
An instrument indicating the spectral amplitude distribution of the input signal over a
desired frequency range, generally by providing a visual display of the amplitude of each
frequency component in relation to its frequency in Cartesian form.
3.5
Transfer oscillator
A stable tunable oscillator whose frequency, either fundamental or harmonic can be made
precisely coherent with the fundamental of the unknown signal.
Using heterodyne techniques, time-variant frequency or phase deviations can be readily observed and
Note. —
measured.
4. Immittance
Term used to cover impedance and/or admittance.
4.1 Immittance charts
4.1.1
Smith chart
A coordinate system consisting of two families of orthogonal intersecting circles bounded
by an outer circle. The chart coordinates display the complete range of possible values of
normalized real and imaginary components of a passive immittance encountered along any
mismatched (electrically) uniform transmission line or waveguide under steady-state
conditions:
jX)/Z„
(R + or
(G + jB),'Yo
where:
Z0
= characteristic impedance
Y0 = characteristic admittance

17 —
The coordinates are arranged so that normalized immittances are graphically related to the
7C radians
phase displacement along the transmission line or waveguide. Angular rotation of 2
(360°) is linearly related to the travel of )L/2 along a transmission line or waveguide.
The radial scale gives reflection coefficient magnitude increasing linearly from zero at the
centre of the chart to unity at the rim.
In this definition only passive immitances are taken into account. It can, however, be extended for the
Note.
representation of immittances having a real part of a restricted negative value. In that case, the outer circle
gives a reflection-coefficient magnitude higher than unity.
4.1.2 Z-theta chart
This chart is similar to the Smith chart except that impedances are represented in polar
form:
I ZI = IR+JXI
O = arc tan X
R
4.2 Microwave multiport junction
A volume generally confined between conductive boundaries, where transmission lines are
coupled electrically and/or magnetically.
4.2.1 Directional coupler
A four-port reciprocal junction, ideally lossless and matched at each port, in which the
power fed into any one port is divided between only two of the other ports.
Ideally no power will be transmitted to the fourth port and none will be transmitted back to the first.
Note. —
4.2.2 Coupling factor (of a directional coupler)
The ratio (generally expressed in decibels) between the power fed into one port and the
power available at another.
In devices where the input power is very unequally divided between two other ports, the coupling factor is
Note. —
conventionally referred only to the less coupled port.
4.2.3 Directivity (of a directional coupler)
The ratio (generally expressed in decibels) of
lling wave propagates between two
the output power at one of the ports, wh
...