1、Rec. ITU-R BO.1295 1RECOMMENDATION ITU-R BO.1295REFERENCE TRANSMIT EARTH STATION ANTENNA OFF-AXIS e.i.r.p. PATTERNSFOR PLANNING PURPOSES TO BE USED IN THE REVISION OF THEAPPENDIX 30A (Orb-88) PLANS OF THE RADIO REGULATIONSAT 14 GHz and 17 GHz IN REGIONS 1 AND 3(Question ITU-R 218/11)(1997)Rec. ITU-R
2、 BO.1295The ITU Radiocommunication Assembly,consideringa) that Resolution 531 (WRC-95) of the World Radiocommunication Conference (Geneva, 1995) invites theITU-R to study the possibilities to improve the efficiency of the Appendix 30A (Orb-88) Plans of the Radio Regulations(RR) by taking due account
3、 of the technological progress;b) that for the feeder link of the broadcasting-satellite service planning purposes a simple transmit earth stationantenna reference pattern is necessary;c) that the existing RR Appendix 30A (Orb-88) Regions 1 and 3 transmit earth station antenna patterns are nolonger
4、appropriate due to technological improvements (see also Recommendations ITU-R S.465, ITU-R S.580 andITU-R S.731);d) that measured data in support of an improved transmit antenna reference pattern is available;e) that the use of antennas with the best achievable radiation pattern will lead to the mos
5、t efficient use of theradio-spectrum and the geostationary-satellite orbit;f) that the transmit earth station antenna in the feeder-link Plans are operated by professional users,recognizinga) that the adoption of improved reference transmit earth station antenna patterns for planning purposes does n
6、otprevent the use of other antennas that have been coordinated or will be coordinated in the future on the basis of differentpatterns;b) that off-axis e.i.r.p. values were used in the development of the RR Appendix 30A (Orb-88) Plans,recommends1 the use of co-polar and cross-polar off-axis e.i.r.p.
7、values given in Fig. 1 together with their associatedformulae provided in Annex 1 for replanning purposes of the RR Appendix 30A (Orb-88) Plans in Regions 1 and 3.2 Rec. ITU-R BO.12951295-010 10 20 30 40 50 70 60A25 25 251 10 102101BBAOff-axise.i.r.p.relativetoE(dB)Off-axis angle, (degrees)FIGURE 1E
8、arth station e.i.r.p. at off-axis antenna anglesCurves A: new transmit earth station co-polarB: new transmit earth station cross-polarA: RR Appendix 30A (Orb-88) Regions 1 and 3 co-polar*B: RR Appendix 30A (Orb-88) Regions 1 and 3 cross-polar* Curves included for information only.FIGURE 11295-01 = 1
9、3 cmANNEX 1Formulae associated to the curves of Fig. 1Curve A: co-polar component (dBW):E for 0 0.1E 21 20 log for 0.1 0.32E 5.7 53.2 2for 0.32 0.54E 28 25 log for 0.54 36.31E 67 for 36.31 Rec. ITU-R BO.1295 3Curve B: cross-polar component (dBW):E 35 for 0 1.91E 28 25 log for 1.91 36.31E 67 for 36.3
10、1 where:E : earth station e.i.r.p. on the antenna axis (dBW) : off-axis angle referred to the main lobe axis (degrees).For replanning purposes, an antenna diameter of 5 m for the band 17.3-18.1 GHz and 6 m for the band 14.5-14.8 GHzare to be assumed.The on-axis gain for the 5 m antenna at 17.3 - 18.1 GHz and for the 6 m antenna at 14.5-14.8 GHz is taken as 57 dBi.
