Disclosure to Promote the Right To Information

Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.

इंटरनेट मानक

“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda

“Invent a New India Using Knowledge”

“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru

“Step Out From the Old to the New”

“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan

“The Right to Information, The Right to Live”

“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam

“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 14630 (1999): Guide for Designing Detail Specificationsof Radio-frequency Coaxial Cables [IEC Title :Radio-frequency Cables, Part 0: Guide to the Design ofDetail Specifications - Section 1 - Coaxial Cables] [LITD6: Wires, Cables, Waveguides and Accessories]

IS14630:1999 IEC96-O-1(1990)

Indian Standard

GUIDE FOR DESIGNING DETAIL SPECIFICATIONS OF RADIO-FREQUENCY

COAXIAL CABLES

[ IEC TITLE : RADIO-FREQUENCY CABLES -PART 0 : GUIDE TO THE DESIGN OF DETAIL SPECIFICXHONS - SECTION 1 -COAXIAL CABLES ]

ICS 33.120.10

0 BIS 1999

BUREAU OF INDIAN STANDARDS

MANAK BHAVAN, 9 BAHADUR SHAH ZAFARMARG

NEW DELHI 110002

Price Group 7 January 1999

Wires, Cables, Waveguides and Accessories Sectional Committee, LTD 18

NATIONALFOREWORD

This Indian Standard which is identical with IEC Pub %-O-l ( 1990 ) ‘Radio-frequency cables -Part 0 : Guide to the design of detail specifications - Section 1 - Coaxial cables’ issued by the International Electrotechnical Commission (IEC), was adopted by the Bureau of Indian Standards on the recommendation of Wires, Cables, Waveguides and Accessories Sectional Committee, LTD 18, and approval of the Electronics and Telecommunication Division Council.

The text of the IEC standard has been approved as suitable for publication as Indian Standard without deviations. Wherever the words ‘International Standard’ appear referring to this standard, they should be read as ‘Indian Standard’.

CROSSREFERENCES

In this Indian Standard, the following International Standard is referred to. Read in its place the following:

International Standard Corresponding Indian Standard Degree of

Equivalence

IJX 68-2: Environmental IS 9000 Basic environmental testing procedures Technically testing, Part 2 : Tests for electronic and electrical items Equivalent

Only the English language text in the International Standard has been retained while adopting it in this Indian Standard.

Indian Standard

IS 14630 : 1999 IEC 96-O-l ( 1990)

GUIDE FOR DESIGNING DETAIL SPECIFICATIONS OF RADIO-FREQUENCY

COAXIAL CABLES

[ IEC TITLE : RADIO-FREQUENCY CABLES -PART 0 : GUIDE TO THE DESIGN OF DETAIL SPECIFICATIONS - SECTION 1 -COAXIAL CABLES ]

1 Scope /

This part of the standard gives recommendations for design parameters, including nominal charac- teristic impedances and diameter over dielectric, and guidance for the design of radio-frequency cdaxial cables with braid, metallic tapes or tubular outer conductors.

2 Register of symbols used

Symbol Designation Unit

Total attenuation per unit length, 20°C .............................. Total attenuation per unit length, T* 2OoC ........................... Attenuation due to element x, 2O’c ................................ Braid angle of element x ...................................... Density of the material of element x ................................ Loss angle of the material of element x .............................. Relative dielectric permittiv.ity of the material of element x ................... Conductivity of the material of element x, 20°C ......................... Thermal resistivity of the material of element x ......................... Braid coverage concerning element x ............................... Velocity of propagation in free space ............................... Capacitance of elementx, per unit length .......... 1 ................. Diameter of individual wires of element x ............................ Outer diameter of element x .................................... Electrical effective diameter of element x ............................. Mean diameter of element x .................................... Maximum permissible voltage gradient of dielectric (peak value) ............... Frequency .............................................. Coating thickness concerning element x ............................. Calculation factors according to tables 2. I and 2.2 ....................... Braid lay length concerning element x ............................... Total weight of cable per unit length ............................... Weight of element x ........................................ Number of stranded wires of inner conductor .......................... Number of wires to each spindle concerning braid x ...................... Number of spindles in the braid concerning element x ..................... Maximum permissible input power, ambient temperature 4O’c ................ Maximum permissible input power, ambient temperature T* 40°C ............. Maximum permissible dissipation power per unit length .................... Filling factor of braid concerning element x ........................... D.C. resistance of conductive element x, per unit length .................... and insulation resistance of insulating element xrespectively ................. Nominal thickness of element x .................................. Minimal thickness of element x .................................. Temperature of element x ..................................... Ambient temperature ........................................ Test voltage (50 Hz), rounded rn1.s. value ............................ Test voltage (50 Hz), calculated r.m.s. value ........................... Discharge test voltage, t.m.s. value ................................ Maximum permissible operating voltage, rounded r.m.s. value ................ Maximum permissible operating voltage, calculated r.m.s. value ............... Velocity ratio ............................................ Characteristic impedance, nominal value ............................

dB/m dB/m dB/m ’ (degree) g/cm3 rad

m/Rmm’ K-m/W

m/s pF/m mm mm mm mm kV/mm MHz mm

mm g/m g/m

W W W/m

R/m MR km mm mm “c ‘c kV kV . kV kV kV ’

n

1

1

IS 14630:1999 IEC 96-O-1(1990)

Numbering of construction elements:

1. Inner conductor

2. Dielectric

3. Outer conductor

4. Sheath

5. Medium between outer conductor and screen

6. Screen

7. Medium between first and second screen

8. Second screeh

etc.

Table 2.1 - Example of use of k, factor

Factor dependent on inner conductor concerning the voltage gradient in the

Thermal dissipation constant of sheath surface in air

W,m2K1.25

Table 2.2 - Exampie of use of kxy factor

Factor

Coating factor I hc

Stranding or braiding factor: I

- concerning attenuation ha

- concerning d.c. resistance and weight kl,

Construction element concerned

Ratio between overall diameter and diameter of individual wires

Effective diameter factor concerning characteristic impedance

hi

hz

6

1

2

3 Material constants

3.1 Table of material constants relating to dielectric and shearh and their materials

Table 3. I

Symbol Designation Unit

Permittivity of dielectric Dissipation factor of dielectric Maximum permissible voltage gradient of dielectric kV/mm Density of

I

dielectric g/cm’ Thermal or sheath resistivity K-m/W Maximum permissible operating “c temperature

” PE - polyethylene PTFE - polytetrafluoroethylene FEP = fluorinated ethylene propylene ETFE = ethylenetetrafluoroethylene PFA = perfluoroalcoxylalkane PVC = polyvinylchloride

2, Typical value(s). 3)

4, 85°C: high density material. 80°C: other density material.

‘) Under consideration. 6)

Frequency (MHz) tan S,

IS 14630 : 1999 IEC 96-O-l ( 1990)

values for different

Value for I)

Solid PE Cellular’) PE PTFE FEP ETFE PFA PVC

2.28 1.3 I.5 1.7 2.1 2.1 2.6 2.1

2.5.10-J 4.10-4 6.10-4 6.10-4 ?I 6) 2) 51

II0 20 20 20 II0 51 51

0.93 0.28 0.44 0.58 2.2 2.2 1.7 2.2 I .4?’

3.5 I5 9 6 4.4 5.0 4.4 4.5 7.0

85/804’ 70 70 70 250 200” 150”

‘) In the case of silvered inner and outer conductors only.

3

IS 14630 : 1999 IEC 96-O-l ( 1990)

3.2 Tables of material constants relating to conductors

Table 3.2.1 - Conductivity (at 20°C) and density

I Material ( Symbols 1 Unit ( Value ( Symbols I Unit ) Value 1

I Copper Aluminium Tin Silver Copper clad steel 30% Copper clad steel 40%

‘) For calculation of d.c. resistance only.

8.3 1.3 61 10.5 17.4”

-l-J

8.15 23.2” 8.20

Table 3.2.2 - Coating factor’)

Conductor I Symbol Value I

Bare copper wire Silvered copper wire Tinned copper wire Copper clad steel wire

I I

kl, and k3, I

Table 3.2.3 Table 3.2.4

‘) RF resistance of ccated wire in relation to bare copper wire, dependent on frequency and coating thickness

Table 3.2.3 - Tinned copper wire

h&or hd_i

0.01 I.01 0.02 I .03 0.03 1.06 0.04 I.1 I 0.06 1.25 0.08 1.44 0.10 1.67 0.12 I.91 0.15 2.24 0.18 2.46 0.20 2.60

LO.25 2.70

kl,orh

Table 3.2.4. - Copper clad steel wire

0.005 II.04 0.010 6.06 0.015 4.16 0.020 3.17 0.025 2.57 0.030 2.16 0.035 I .87 0.040 1.65 0.050 1.35 0.060 I.16 0.070 1.04 0.080 1.00

‘) Assumptions relating to steel: x - 8 m/Rmm2. Relative permeability, p, - 200.

.

4

IS 14630:1999 IEC 96-O-1(1990)

3.3 Construction constants

3.3.1 Table of construction constants relating to inner conductor

Table 3.3. I

Symbol Designation Value versus number of strancis (IV,)

I 7 12 19

/ 1.00 I 1.03 I 1.03 I 1.03 I

Stranding factor for attenuation / 1.00 / I.25 ( 1.25 1 1.25 1

r- hz I Effective diameter factor 1 1.00 1 0.94 1 0.96 1 0.98 1

I kid I Ratio between overall diameter and diameter of individual wires / 1.00 / 3.02 1 4.16 1 5.00 j

r-k2 I Voltage gradient factor I 1.00 I 0.90 I 0.90 ( 0.90 (

3.3.2 Tableof construction constants relating to braided outer conductors and screens

Table 3.3.2

Braid angle &; 86 b 4 -.-

D3m ’ D6m

k3,; k,

20” 8.63 1.06 25” 6.74 I.10 30” 5.44 I.15 35” 4.49 1.22 40” 3.74 I .30 45” 3.14 1.41

Definitions:

4, = I

Jl + (n LJ3, / L3)7 - - cos /33

I

cos 86

3.4 Braid wire dimensions

Table of braid wire dimensions of outer conductor and screen

Table 3.4

Nominal outer diameter of Nominal diameter of braid wire (dj, 4) dielectric (9) mm

mm Single braid Double braid

0.87 and I .5 0.09-O. I 1 2.95,3.1,4.8 and 6.4 0.13-0.15 0.13-0.15 1.25.9.8 and 1 I.5 0.18-0.20 0.16-0.18 17.3 0.24-0.26 0.18-0.20

5

IS 14630 : 1999 IEC 96-O-l ( 1990 )

3.5 Attenuation factors

Table 3.5 - Factor relating to calculation of attenuation

Symbol Designation

Attenuation due to inner

Attenuation due to outer conductor

Feature

Solid wire Stranded wire

Tinned copper wires Copper clad steel wire

Tubular outer conductor Braided outer conductor

Braid wires tinned copper

Value

1.0 1.25

See table 3.2.3 See table 3.2.4

1.0 2.0”

See table 3.2.3

‘) Rough approximation (in absence of a reliable theory).

3.6 Maximum permissible input power

8

6

16 ;0 ;4

Outside diameter of cable 04 (mm)

,

Figure 1 - Graph for calculation of maximum permissible input power

6

IS 14630 : 1999 IEC 96-O-l ( 1990)

4 Standard values of characteristic impedance and outer diameter of dielectric

4.1 Nomintil characteristic impedance of coaxial cables

All impedances specified in this clause are defined at a frequency of 200 MHz (MC/S) and at the reference temperature of 20 “C.

Standard values of nominal characteristic impedance are:

500

93 R

750

4.2 Nominal diameters over dielectric of coaxial cables

Nominal diameters & over dielectric and the tolerances thereon shall be in accordance with the following table:

Table 4

Nominal value

0.87 1.50 2.95 3.70 4.80 6.40 7.25 9.80 II.50 17.30

Tolerance f 0.07 0.10 0.13 0.15 0.20 0.20 0.25 0.25 0.30 0.40

5 Cable construction details

5.1 General

The starting point is to determine:

a) the nominal characteristic impedance, z, (according to 4.1);

b) the outer diameter of dielectric, & (according to 4.2):

c) the permittivity of dielectric, ~2 (table 3. I).

Calculate the effective diameter of outer conductor, L&.

Table 5.1 - Special design features

5.2 Inner conductor

The electrical effective diameter DI, of the inner conductor follows from:

DI, - he exp (-z, )&O)r)

Table 5.2

Special design features

Solid inner conductor Diameter DI as calculated

Stranded inne-conductor Diameter DI > @,(see 5.3)

1) Rounded up from 59.96.

IS 14630 : 1999 IEC 96-O-l ( 1990)

5.3 Stranded inner conductor

The diameter DI is to be calculated from the effective diameter L&:

DI * &/kl,

The wire diameter dl is to be calculated from DI:

dl - Dl/kld

kid and kl, according to table 3.3. I.

5.4 Braided outer conductor

Table 5.4

The effective diameter 4,

outer diameter Dl mean diameter D3rn

are to be calculated from the outer diameter of dielectric Q and the diameter of the braid wires 4:

Q. -Q+ l.5dJ Q - Q + 4.5 4 Q, - Q + 2.25 d3 d3 according to table 3.4

I The filling factor of the braid is:

I N3 n3 d3 k3r 93 *

2n DInI _... d, and Q, as above k>, according to table 3.3.2

The coverage and the braid angle of the outer conductor are given by:

B3 - 293 - *2 /Is - arc tan 7[ D& 4

5.5 Medium between ourer conductor and screen

Table 5.5

The outer diameter of the interposed medium is:

Ds-4+2s5

5.6 Braided screen

Table 5.6

The outer diameter Q and the mean diameter De,,, are to be calculated from the outer diameter of the interposed medium Ds and the diameter of the braid wires, da:

06 - Ds + 4.5 &

Dh,,, - Ds + 2.25 4 &, according to table 3.4

The filling factor of the braid is:

N6nbdbk

*- 2x4,

4 and Q,,, as above kr according to table 3.3.2

The coverage and the braid angle of the screen are given by:

& - 296 - 462 & - arc tan n&&b

8

IS 14630 : 1999 IEC 96-O-l ( 1990)

5.7 Sheath

Table 5.7

Material I Outer diamet:; of screen,

I

Nominal thickness 4

I

Minimum thickness

06 4 min.

FEP <2.5 0.25 mm 0.15 mm

2.5-5.9 0.25 mm PTFE 0.38 mm

6.0-9.0 0.30 mm

PE

PVC

<2.s 0.07 Da” + 0.3 mm 0.9 ~~-0. I mm

A2.5 0.07 D6” + 0.5 mm

” Cables without screen: to be replaced by outer diameter of outer conductor D,.

5.8 Weight calculation

The approximate total weight of the cable is to be calculated from m - C mx.

For the calculation of the individual weights, formulae are given in the following table:

Table 5.8

Solid inner conductor ml yl according to table 3.2.1

I Stranded inner conductor mi -i ff! - NI kh YI I , kl, according to table 3.3.1

r-- I n according to table 3.1 DI according to 5.3

Tubular outer conductor m3-n(&+~)53n n according to table 3.2.1

Braided outer conductor nh - i d3 N3 m kjr i kj, according to table 3.3.2

Interposed medium between outer ms - n (& + 55) 4 n

y5 dependent on the material used

conductor and screen L& according to table 5.4

I Braided screen I y6 according to table 3.2.1 k, according to table 3.3.2

I-- Sheath nq - n (4 + 54) s4 y4” y4 according to table 3.1

I) For cables without &xn, 4 is to be replaced by 4.

9

IS 14630 : 1999 IEC 96-O-l ( 1990)

6 Calculation of electrical properties

6. I D. C. resistance of conductors and screen, per unit length

The values are to be calculated from the formulae in the following table:

Table 6.1

Solid inner conductor

Stranded inner conductor

4 R, --

n @XI

RI 4 ki, I-

Nnd;?xI

I

XI. ~1, ~6 according to table 3.2. I

kt, according to table 3.3. I

k3, and kr according to table 3.3.2

Q and 4 according to table 3.4

Tubular outer conductor

Braided outer conductor R3 - 4 h,

NJ n3 n 4 x3

Braided screen

6.2 Attenuation

The total attenuation per unit length is to be calculated from:

a! - aI + a2 + a3

where al, a2 and a3 are the attenuation components due to the inner conductor, dielectric and outer conductor. The attenuation is related to a cable temperature of 20°C. For temperatures T+ 2O”C, the attenuation ar shall be calculated by:

a~-(a~+a3)JI+0.00393(T-20OC)+a2

NOTE - a? may be temperature dependent for some dielectric materials.

Formulae for calculation of al, a2 and a3 are given in the following table. These formulae are applicable for frequencies L 10 MHz. Formulae for lower frequencies are under consideration.

Table 6.2

4.58 kl, kt, ,m

” - DI, In D~DI, ’ y

02 - 9.l& . tan &f

4.58 k,, k,, y:Ez/

a3 _ 4. In D,,/D,. * 7

XI and ~3, kl, and k,, according to tables 3.2.1 et 3.2.2

kl. and kj, according to table 3.5

~2 and tan & according to table 3.1

D,. and 01. according to Subclause 5.2 and table 5.1 or Subclause 5.4

6.3 Nominal characteristic impedance z, and capacitance C2 per unit length

C2 = %. 104 (pF/m)

~2 according to table 3. I;

03, according to table 5. I or to 5.4;

DI, according to 5.2.

I) Rounded up from 59.96 and 2.9979 respectively.

IS 14630 : 1999 IEC 96-O-l ( 1990 )

6.4 Calculation of power rating

The power rating shall be calculated from the attenuation and the maximum permissible dissi- pation power for an ambient temperature of 40°C.

The maximum permissible dissipation power per unit length (Pd) is dependent on the maximum permissible temperature Tt of the inner conductor, given by the maximum permissible temperature of dielectric (see table 3.1).

The temperature rise of the inner conductor above that of the stagnant ambient air is:

Pd

T1-40”c=2n

aI + ‘/2 al

a

a2 and 04 according to table 3. I;

k4 according to figure I, page 6

For cables without screen, 06 is to be replaced by 4.

The first term of the sum is the temperature rise of inner conductor above sheath surface (Tr- T4). The second term is the temperature rise of sheath above ambient air (fi- &).

A graphical solution of this equation is proposed.

Having found Pd, the maximum permissible input power is given by:

aT according to 612.

868.6 Pd 395 Pij A0 = ~ - -

2.2 aT aT

The maximum attenuation may be 10% above the nominal value. Because of the unknown temperature of the outer conductor, the calculation assumes equality with the temperature of the inner conductor. The resulting error is negligible.

For ambient temperatures Ta z 4O”c, the power rating shall be calculated from PRO by the empirical formula:

6.5 Permissible voltages

6.5.1 Test voltage, dielectric, U,

The maximum value of voltage gradient is to be found at the surface of the inner conductor. It is limited by the maximum permissible voltage gradient E2 of the dielectric. Hence the test voltage Ut, (r.m.s. value) is to be calculated from the formula:

E2 according to table 3. I;

k2 according to table 3.3.1;

D, according to 5.3:

DI, according to 5.2;

DJ~ according to table 5. I or to 5.4.

The value of U,, shall then be rounded to the nearest 0.2 kV for values below 5 kV and to the nearest

11

1s 14630:199Y IEC 96-O-1(1990)

0.5 kV for values of 5 kV and more. The rounded test voltage is designated U,. The rounded test voltage shall be applied for 2 min at a frequency of 40 Hz to 60 Hz.

6.5.2 Discharge test voltage, dielectric, r/d

The discharge test voltage Ud (r.m.s. value) is given by the formula Ud = 0.5 Ut except in the case for polytetrafluoroethylene.

Ud - 0.4 U! with a minimum of I kV

6.5.3 Maximum permissible operating volrage. U,

The maximum permissible operating voltage U, (r.m.s value) is derived from the test voltage U,.

UO,, = 0.45 lJ,

as far as the maximum permissible input power f’40 will not be exceeded. The condition

U,Li’z,/ 1000

has to be met in each case. The value of U,, shall then be rounded to the nearest 0.2 kV for values below 5 kV and to the nearest 0.5 kV for values of 5 kV and more. The rounded maximum permissible operating voltage is designated &.

6.5.4 Test voltage, sheath

For PVC sheaths:

Table 6.5

Nominal thickness of the sheath ($4)

mm

Test voltage (kV r.m.s.)

Immersion test Spark test

Up to and including 0.5 No test No test Over 0.5 up to and including 0.8 2 3 Over 0.8 up to and including 1.0 3 5 Over I .O 5 8

6.6 Insulation resistance

Rz L 10.000 MQkm

12

IS 14630 : 1999 IEC 96-0-l t 1990 I

7 Climatic and mechanical robustness

7. I Tests

Table 7. I

Item

Capacitance stability

Attenuation stability

Thermal stability

Dimensional stability

Flow test

(For dielectric of solid PE. 1.5<D~<l7.3only)

Stability to ultraviolet rays

Details to be included in detail specification

High and low temperature” Maximum admissible variation of capacitance

High and low temperature”

Test Frequency Maximum admissible increase of attenuation (where applicable, preferably 0.3 dB/m and I.5 dB/m at a frequency of3000 MHz)

Conditioning temperature:

- for solid PE: 80(85) fZ”C?’ - for other materials: ”

The permissible displacement between the end faces of inner conductor and dielectric is to be indicated

The minimal value of the applied force is given by the empirical expression:

The calculated value is to be rounded up to the nearest 5 N

Under consideration

I) Temperatures shall preferably correspond to those of IEC Publication 68-2: - Test A (-65, -55, -40. -25, - IOC): - Test B(+ZOO, + 155. + 125, + 100, +85, +70. +55. +400c).

*r According to table 3.1, note 4.

7.2 Operating data

Table 7.2

Minimum bending 5 x 04 for single indoor laying radius IO x D4 for single outdoor laying

Minimum coiling diameter

Minimum permissible laying temperature

- I5 ‘c dielectric PE. sheath PVC quality I -40°C dielectric PE, sheath PVC quality 2 -55’c dielectric and sheath FEPand PTFE

Cautious laying without shocks recommended

13