1、 Recommendation ITU-R S.732-1(12/2012)Method for statistical processing of earth station antenna side-lobe peaks to determine excess over antenna reference patterns and conditions for acceptability of any excessS SeriesFixed-satellite servicesii Rec. ITU-R S.732-1 Foreword The role of the Radiocommu
2、nication Sector is to ensure the rational, equitable, efficient 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 regulator
3、y and policy functions of the Radiocommunication Sector are 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/I
4、TU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. 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
5、/ISO/IEC and the ITU-R patent information database can also 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)
6、BT Broadcasting service (television) F Fixed service M Mobile, 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
7、 fixed-satellite and fixed service systems SM Spectrum management 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 Pu
8、blication Geneva, 2013 ITU 2013 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R S.732-1 1 RECOMMENDATION ITU-R S.732-1 Method for statistical processing of earth station antenna side-lobe peaks to determine ex
9、cess over antenna reference patterns and conditions for acceptability of any excess (1992-2012) Scope This Recommendation sets forth a method for the statistical processing of earth station antenna side-lobe peaks in order to determine the percentage of side-lobe peaks that exceed antenna reference
10、patterns provided in relevant ITU-R Recommendations. It also recommends conditions under which earth station antenna side-lobe patterns with peaks exceeding recommended envelopes will still be considered as compliant with ITU-R Recommendations that allow a certain percentage of side-lobe peaks to ex
11、ceed the recommended envelopes. The ITU Radiocommunication Assembly, considering a) that in determining the coordination distance or for assessing the interference between earth stations and radio-relay stations, and for coordination studies between earth stations and space stations of different sat
12、ellite systems sharing the same frequency bands, it is necessary that the gain of the earth station antenna be known in the relevant direction; b) that in the case of interference calculations between satellite systems, it may be desirable to know the radiation characteristics of the antenna in plan
13、es other than the principal plane; c) that in calculating mutual interference between radio-relay systems and satellite communication systems, particularly when there is more than one interference source, it is preferable that the statistical properties of antenna side-lobe levels, as well as side-l
14、obe peaks, be known; d) that while ITU-R Recommendations on antenna radiation patterns may contain provisions allowing side-lobe peaks to exceed the recommended envelope, these provisions have no connection with the calculation of potential mutual interference in the course of coordination; e) that,
15、 in compiling statistical data, it is necessary to protect the integrity of such data from experimental errors, recognizing a) that Recommendation ITU-R S.580, which addresses earth station antenna design objectives, allows a certain percentage of side-lobe peaks to exceed the reference pattern; b)
16、that Recommendations containing reference antenna patterns used for interference analysis and coordination between geostationary-satellite networks allow side-lobe peaks to exceed the reference pattern only under specified circumstances (e.g. in the spillover regions, as Recommendation ITU-R S.731,
17、and local ground reflections at large off-axis angles, as Recommendations ITU-R S.465 and ITU-R S.1855), 2 Rec. ITU-R S.732-1 recommends 1 that the following method should be used for processing measured data on side-lobes of earth station antennas in the case where ITU-R recommended reference anten
18、na radiation patterns allow a certain percentage of side-lobe peaks to exceed the pattern: 1.1 that a side-lobe peak be defined as a local gain maximum for which an increase or a decrease in off-axis angle shows a reduction in gain level of at least 2 dB (see Note 1); 1.2 the angular regions (sample
19、 windows) within which side-lobe peak samples are taken should be defined as those shown in Table 2; NOTE 1 These “peaks“ can be either above or below the allowed reference antenna pattern. 2 that measurement samples affected by experimental errors should be disregarded; 3 that the minimum angular r
20、esolution of antenna side-lobes measurement in Table 1 should be used so that all side-lobes are captured: TABLE 1 Minimum measurement resolution Antenna size Measurement resolution for off-axis angle , min 30 Measurement resolution for off-axis angle , 30 250, when the largest dimension of the phys
21、ical aperture is greater than 12 m, the required angular measurement resolution is 0.1 for all off-axis angles. Further studies may be necessary to determine the maximum size of the physical antenna aperture above which 0.05 resolution measurements are not practical. 4 that the peak gain value of th
22、e side-lobes within each sample windows should not exceed the reference patterns by more than Y dB, with Y given in Table 2: TABLE 2 Angular regions (sample windows) for processing measured side-lobe peak samples and allowed excesses Angular regions/sample windows Angular limits () Allowed excess (Y
23、 in dB) W1min 7 1 W27 9.2 3 W39.2 48 3 W448 180 10 In Table 2, the lower limit of the first angular region W1is 1 or (100 /D) degrees, whichever is greater; Rec. ITU-R S.732-1 3 5 that when the number of side-lobe peaks is less than 10 in the specified angular regions, the percentage of side-lobe pe
24、aks of the earth station antenna that do not comply with the reference pattern should be determined using the following expression: =NiWijX1(%) 100 where: j: index of the angular region Wanalysed, which varies from 1 to 4 according to Table 2 N: number of side-lobe peaks exceeding the reference patt
25、ern within angular region j i: width of the ithside-lobe peak sample that exceeds the reference pattern (degrees) W: total sampled angular width of angular region j (degrees); 6 that antennas be deemed to be compliant with the reference antenna pattern if they meet the condition stated in recommends 4 and the percentage of side-lobes exceeding the reference antenna pattern does not exceed the allowed limit or, in the cases covered by recommends 5, no value of Xjexceeds the allowed percentage of excess.
