ITU-R SM 2028-2012 Protection distance calculation between inductive systems and radiocommunication services using frequencies below 30 MHz《频率低于30 MHz的无线电通信业务和感应系统之间的保护距离计算》.pdf

《ITU-R SM 2028-2012 Protection distance calculation between inductive systems and radiocommunication services using frequencies below 30 MHz《频率低于30 MHz的无线电通信业务和感应系统之间的保护距离计算》.pdf》由会员分享，可在线阅读，更多相关《ITU-R SM 2028-2012 Protection distance calculation between inductive systems and radiocommunication services using frequencies below 30 MHz《频率低于30 MHz的无线电通信业务和感应系统之间的保护距离计算》.pdf（11页珍藏版）》请在麦多课文档分享上搜索。

1、 Recommendation ITU-R SM.2028(09/2012)Protection distance calculation between inductive systems and radiocommunication services using frequencies below 30 MHzSM SeriesSpectrum managementii Rec. ITU-R SM.2028 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, eff

2、icient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector a

3、re performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1.

4、 Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can al

5、so be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mo

6、bile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum ma

7、nagement SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2012 ITU 2012 All rights reserved. No p

8、art of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R SM.2028 1 RECOMMENDATION ITU-R SM.2028 Protection distance calculation between inductive systems and radiocommunication services using frequencies below 30 MHz (2012) Scope This Recommen

9、dation addresses the compatibility between inductive systems operating at frequencies below 30 MHz and the existing radiocommunication services and provides a summary of a straightforward procedure to calculate the protection distance to protect radiocommunication services with regard to interferenc

10、e by inductive systems. The ITU Radiocommunication Assembly, considering a) that there is an increasing demand for the usage of inductive systems including induction cooking appliances which are operating at the frequency bands below 30 MHz; b) that there is interference potential of inductive syste

11、ms to the existing radiocommunication services; c) that the protection distance of radiocommunication services should be established to assess the impact of interference from inductive systems, noting a) that Recommendation ITU-R SM.1056 considers the latest edition of CISPR Publication 11, “Protect

12、ion range calculation between inductive systems and radiocommunication services using below 30 MHz”, as a guide for the application of limits and methods of measurements for ISM devices in order to protect radiocommunications; b) that Report ITU-R SM.2180 Impact of industrial, scientific and medical

13、 (ISM) equipment on radiocommunication services, introduces applications of ISM equipment, characteristics of radiation and analysis of potential interference to emphasize on the protection of radiocommunication services from ISM equipment, recommends 1 that administrations take all necessary precau

14、tions to ensure that inductive systems operating on frequency bands below 30 MHz should not cause interference to radiocommunication services; 2 that in establishing protection method of radiocommunication services, administrations should take into account a calculation procedure of protection dista

15、nce between inductive system and radiocommunication services, as given in Annex 1. 2 Rec. ITU-R SM.2028 Annex 1 A method of protection distance calculation 1 Interference scenario model In general, the effective radiated power level of inductive systems can be calculated from magnetic dipole moment.

16、 The magnetic dipole moment which is the product of the total current in the inductive loop multiplied by the surface area can be determined from the measured magnetic field strength at a certain distance by using Maxwell equations. The radiated power level can be applied to existing service as an i

17、nterferer. The electric field strength of interference from inductive system should be less than the interference limit of electric field strength of victim service. Thereby it is required that the protection distance be defined to protect the existing service. The practical interference scenario is

18、 shown in Fig. 1. FIGURE 1 Interference scenario model SM.2028-01InductivesystemCoaxialxmyzCoplanarERPHmMeasurementequipmentRadioreceiverdrElimitHlimitRec. ITU-R SM.2028 3 2 Calculation procedure of radiated power of an inductive system The magnetic field strength Hm (A/m)1of an inductive system is

19、measured by measurement equipment at a certain distance d (metres) and it has two radiation directions as coaxial direction and coplanar direction. The coaxial direction is on the axis of the inductive loop and the coplanar direction is in the plane of the loop. In addition, the radiation direction

20、is determined by the cross-over point of the coaxial curve and the coplanar curve. The cross-over point is positioned at 2.354 r(metres) from the magnetic dipole. Here,rmeans the radian wavelength which is equal to /2and is the wavelength. When the magnetic field strength is measured at a shorter di

21、stance than the cross-over point, the magnetic dipole moment m1 (Am2) in the coaxial direction can be calculated: 22312ddHmrrm+= (1) When the magnetic field strength is measured at a longer distance than the cross-over point, the magnetic dipole moment m2(Am2) in the coplanar direction can be comput

22、ed by: 42243224dddHmrrrm+= (2) The effective radiated power (ERP) (kW) level of an inductive system can be derived: 24)(2010001mERPr= (3) Here, m is the maximum of m1and m2. 3 Calculation of electric field strength limit of a victim service There are two ways to determine the electric field strength

23、 limit of a victim service Elimit (dB(V/m). One is to consider the noise level and another is to consider the signal-to-noise ratio (SNR). The method considering noise level is as follows. Enoise(dB(V/m) of a victim service is corrected for the bandwidth of the victim receiver: ()noisevictimbnoiseno

24、isebbEE /log10,+= (4) Here, bnoiseis the measuring bandwidth of noise, bvictimis the bandwidth of victim and Enoise,bis electric field strength of noise from Recommendation ITU-R P.372. In case of broadband interference, the bandwidth ratio (BWR) (dB) should be included to calculate the electric fie

25、ld strength limit: BWREEnoiselimit+= (5) The bandwidth ratio is defined: ( )victimmeasuringbbBWR /log10= (6) Here, bmeasuringis the measuring bandwidth of interferer. 1The unit of the limits and measurement of the magnetic field strength quoted in dB(A/m) is equivalent to 20 log H (A/m) + 120. 4 Rec

26、. ITU-R SM.2028 When the bandwidth of the interfering signal is not wider than the victim receiver bandwidth, BWR = 0 dB should be assumed. The method considering SNR is as follows. In the case where the minimum field strength Emin(dB(V/m) and the SNR (dB) are known, the electric field strength limi

27、t is calculated: BWRSNREEminlimit+= (7) From the electric field strength limit, the magnetic field strength limit Hlimit(A/m) can be obtained: 205.5112010=limitElimitH (8) 4 Protection distance calculation for propagation model The complete coverage range can be divided into four sub-ranges. Usually

28、, the propagation models are described as ground wave model and free space model. At distances less than a roll-off of 40 dB/decade, r dtr and r r 2.354, the protection distance (metres) can be calculated: 40101000limitintEEr= (9) where dtr (metres) is the transition distance at the point of interse

29、ction between a roll-off of 40 dB/decade and a roll-off of 20 dB/decade. Eint(dB(V/m) is interference level at a distance of 1 km and can be calculated: dBasymptoteintERPEE +=40,(10) where Easymptote,40(dB(V/m) is determined by 40 dB/decade asymptote at 1 km distance for a radiated power of 1 kW as

30、in Recommendation ITU-R P.368 and ERPdB(dB(kW) is obtained by 10log(ERP). At distances of a roll-off of 20 dB/decade, r r 2.354, the protection distance is calculated by using the following formula: 205.4912010limitdBEERPr+= (11) When the ranges are close to the near field, r r, the protection dista

31、nce is determined: =2rlimitHmr (12) When the ranges are within the near field, r r, the protection distance can be calculated by the following equation: 32limitHmr= (13) Rec. ITU-R SM.2028 5 5 Flow chart for protection distance calculation A simple procedure of protection distance calculation is exp

32、lained in terms of a flow chart: SM.2028-FlowStartEndInput, , , , SNR, Victim locationHdE EmnoiseminCoaxial CoplanarmHd1= 2|mr3+r22dmHd2= 4 |mr2 3mmm = max ( , )12ERP m = 120()21 000 r4VictimlocationEElimitnoise= BWR+E min SNR + BWRHlimit= 1020Ground wave Free spaceEE ERPint asymptote dB= + , 40 40

33、dB decade/ 20 dB decade/ Closed to the near field Inside the near fieldr = 1 000 1040r = 10 20r =Hlimit r2 mr = 32Hlimitm 20 dB decade/r = 10 Closed to the near fieldr =Hlimit r2 m Inside the near fieldr = 32HlimitmrrddElimit 120 51.5E Eint limit120 + 49.5 + ERP EdB limit20120 + 49.5 + ERP EdB limit

34、6 Rec. ITU-R SM.2028 Table 1 describes the Easymptote,40presented in Recommendation ITU-R P.368. TABLE 1 Data presented in Recommendation ITU-R P.368 Table of field strength of the 40 dB/dec. roll-off asymptote at the distance of 1 km by an effective radiated power of 1 kW (symbolic value for long p

35、ath calculation), derived from Recommendation ITU-R P.368 (dB(V/m): Easymptote,40Ground type 1 2 3 4 5 6 7 8 9 10 11 1 5 3e330e310e33e31e33e41e430e610e6 80 70 80 40 30 22 15 7 3 3 3 10 kHz 166 166 165 167 165 165 165 164 163 159 151 15 164 165 164 165 163 164 164 163 160 154 144 20 163 164 163 164 1

36、63 163 163 162 157 149 139 30 162 163 162 163 162 163 161 158 152 142 132 40 162 162 161 162 161 162 160 155 148 137 128 50 161 161 159 162 161 161 158 152 144 133 124 75 160 160 157 161 159 158 154 146 137 126 119 100 159 159 155 160 158 156 150 142 132 121 116 150 158 158 151 158 156 153 144 134 1

37、24 115 112 200 158 158 147 157 154 148 140 129 119 111 109 300 157 157 141 155 150 142 132 122 112 107 106 400 156 156 136 153 147 135 127 117 107 104 103 500 156 155 132 150 143 134 123 113 103 102 102 750 154 154 126 146 137 127 117 107 98 98 98 1.0 MHz 152 153 122 142 132 120 112 103 96 96 96 1.5

38、 151 153 118 135 124 114 107 98 92 92 92 2.0 150 152 115 129 119 109 103 95 89 89 89 3.0 147 151 111 123 112 103 98 93 86 86 86 4.0 144 149 108 117 107 99 95 90 83 84 83 5.0 142 148 107 113 103 97 93 87 81 82 82 7.5 136 146 103 105 97 93 89 84 78 78 78 10 132 143 101 100 94 90 87 81 76 76 76 15 126

39、138 97 95 89 87 83 77 72 72 72 20 120 134 95 91 87 84 81 75 70 70 70 30 113 127 91 87 83 80 77 72 66 66 66 Here, and are conductivity and permittivity, respectively. Rec. ITU-R SM.2028 7 6 Example This section shows an example of the protection distance between induction cooking appliances (interfer

40、er) and AM broadcasting receivers (victim) at 30 MHz using the presented calculation method. CISPR Publication 11 contains the limit of radiation generated by induction cooking appliances and the radiated H-field limits of CISPR Publication 11 in Table 2 and Fig. 2 are used for the interference leve

41、l of induction cooking appliances. The external radio noise is used as the protection criteria of AM receiver in this example. Note that the protection criteria may be changed depending on a variety of victim receiver performance criteria. TABLE 2 Limits of the magnetic field strength Frequency rang

42、e (MHz) Limits at 3 m distance quasi-peak (dB(A/m) 0.009 0.07 69 0.07 0.1485 69 decreasing linearly with logarithm of frequency to 39 0.1485 4 39 decreasing linearly with logarithm of frequency to 3 4 30 3 The limits of this apply to induction cooking appliances intended for commercial use and those

43、 for domestic use with a diagonal diameter of more than 1.6 m. The measurements are performed at 3 m distance with a 0.6 m loop antenna as described in 4.2.1 of CISPR 16-1-4. The antenna shall be vertically installed, with the lower edge of the loop at 1 m height above the floor. FIGURE 2 Limit of t

44、he magnetic field strength SM.2028-02Frequency (MHz)0.01 0.1 1 10100102030405060708090AM broadcastingH-field(dB(A/m)308 Rec. ITU-R SM.2028 The interference level of 18 dB(A/m) for induction cooking appliance is determined according to frequency of AM broadcasting (1 MHz) in Fig. 2. In this case, the

45、 limit of magnetic field strength of 18 dB(A/m) can be assumed to be measured at the distance of 3 m. In CISPR Publication 11, the measuring bandwidth is 9 kHz for frequency range from 150 kHz to 30 MHz and the measuring distance is 3 m. Therefore, it is defined that bmeasuringis 9 kHz and d is 3 m.

46、 Easymptote,40of 120 dB(V/m) is obtained from 1 MHz frequency and ground type 6 in Table 1. The noise level approach is used to get Elimit. The Enoise,bof 9 dB(V/m) and the bnoiseof 2.7 kHz are given in Recommendation ITU-R P.372. The bvictimof 4.4 kHz is used for AM broadcasting. The Enoiseof 11.12

47、 dB(V/m) and BWR of 3.11 dB are calculated by using equations (4) and (6), respectively. Then Elimit, maximum allowable interference level, is obtained as 14.23 dB(V/m) by using equation (5). When the electric field strength at 1 km distance from ERP of 1 kW is given as 109.5 dB(V/m) for the roll-of

48、f of 20 dB/decade in Recommendation ITU-R P.368 and Easymptote,40is 120 dB(V/m), the dtr of 3 349.65 m is computed by 1000 10(109.5 120)/20. Finally, the protection distance (r) is obtained by computing the effective radiated power (ERPdB) and the magnetic dipole moment (m) as in 4. Rec. ITU-R SM.20

49、28 9 TABLE 3 Calculation of protection distance Input data Frequency 1 000 kHz Magnetic field strength (Hm) 18 dB(A/m) Measuring distance (d) 3 mEasymptote,40from Recommendation ITU-R P.368 (see equation (10) 120 dB(V/m) Electric field noise level from Recommendation ITU-R P.372 (Enoise, b) 9 dB(V/m) in 2.7 kHz Bandwidth of the victim receiver (bvictim) 4.4 kHz Measuring bandwidth (bmeasuring) 9 kHz Result Maximum allowable interference l