1、 STD.BSI BS EN bL114-2-ENGL L777 Lb2qbbS Ob25L57 401 BRITISH STANDARD Methods of Measurement on receiving antennas for satellite broadcast transmission in the lu12 GHz band Part 2. Mechanical and environmental tests on individual and collective receiving antennas % x vi The European Standard EN 6111
2、42 : 1996 has the status of a British Standard ICs 33.120.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 61114-2 : 1997 1996 IEC 1114-2 STD.BS1 BS EN bLLL4-2-ENGL 1997 m Lb211bb9 0625Lb 123 m BS EN 61114-2 : 1997 Amd. No. National foreword Date Text affected This Bri
3、tish Standard, having been prepared under the direction of the Electrotechnical Sector Board, was publiched under the authoriw of the Standards Board and comes int effect on 15 July 1997 O BSI 1997 ISBN O 680 27778 X This British Standard is the English language version of EN 611142 : 1996. It is id
4、entical with IEC 11142 : 1996. The UK participation in its preparation was entrusted to Technical Committee EPUl00, Audio, video and multimedia systems and equipment, which has the responsibility to: - aid enquirers to understand the text, - present to the responsible internationavEuropean committee
5、 any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; - monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-referen
6、ces Attention is dram to the fact that annex ZA lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Caalogue under the section ent
7、itled International Standards Correspondence Index, or using the %in b) salt solution tank; c) atomizer: d) thermal controller; e) humidifier. _. II The test chamber shall comply with the requirements given in IEC 68-2-1 1. The test chamber shall have a capacity that can contain the antenna under te
8、st or substitutional specimens for the antenna components. E E I - - _. * * The salt mist shall flow horizontally. cn The atomizer, air supply and salt solution shall comply with the requirements given in IEC 68-2-1 1. 5 Methods of measurement 5.1 Wind load at operating wind velocity 5.1.1 Method of
9、 measurement a) The antenna under test is installed on a rigid antenna test fixture, as shown in figure 1. The centre part of the reflector is directly supported by the fixture and the periphery of the reflector is connected to the fixture by means of springs at four points, that is at the upper edg
10、e, the lower edge, the right side edge and the left side edge. There shall be an apparatus to apply forces to a primary radiator in vertical and horizontal directions. b) The antenna under test with its fixture is set up in a test site according to clause 4 of 1EC 11 14-1 , for the measurement of th
11、e antenna gain. c) Measure the antenna gain or the figure of merit (G/T) with no wind load. d) Apply forces W, and W, to the reflector and the primary radiator according to the procedure shown in table 2. The values of UV, and W, are calculated from the following equations: STD.BSI BS EN b1114-2-ENG
12、L 1777 m Lb24bbS Ob25Lb8 414 m Page 8 EN 61114-2 : 1996 where Al A, V= Vo is the operating wind velocity (m/s). is the maximum wind exposure area for the reflector (m2); is the maximum wind exposure area for the primary radiator, the SHF converter and the supporting structures of the primary radiato
13、r (m2); Table 2 - Test sequence Push all Sideward 1 I 4 Pull all I Sldeward e) Measure the antenna gain or Om, while applying the above forces. NOTE - The following cross-polarization characteMcs are measured in countries where cross-polarized waves are used or Interfering signals from other satelli
14、tes may be received: a) the gain or W for each polarization; b) the radiation dlagram for each polarization; c) the cross-polarization discrimination. 5. I .2 Presentation of resuits The results shall be listed in a table. An example of the table is shown in table 3. NOTE -Table 3 will be modlfied f
15、or the tests described in the note of 5.1.1. STD-BSI BS EN bL114-2-ENGL 1777 Lb24bb7 0625Lb9 350 Page 9 EN 61114-2 : 1996 Test item Table 3 - An example of the list of test results Test result Antenna gain or d or dBM Observation QIT change) - operating wind velocity - survival wind veioctty - destN
16、ctive Wind veloclty Vibration Vibration at mechanical resonant frequency impact Heat cyde Waterproof Salt mist Sulphur dioxide I I I -*- - - - I Windload Remark 1) If the antenna under test Is a multiple beam antenna andor can receive waves of more than two poiarizatlons. the maximum value of the ga
17、in changes or G/T changes for all beams andor polarizations shall be recorded. 2) f, f, and fn are the lowest, mid and highest frequencies respectively, in aie 11/12 GHr band. as specified by the standard of the country or countries for whlch the antenna under test was designed. If any mechanical ch
18、anpe Is observed. It shall be described In detall In the observation column. 5.2 Wind load at survival wind velocity 5.2.1 Method of measurement a) Measure the gain or G/T of the antenna under test. b) Install the antenna under test on a rigid antenna fixture at its centre part, and position the ape
19、rture horizontally and upward as shown in figure 2a. c) Put sand bags uniformly on the reflector so that force Wl is applied to the reflector. The value of Wl is given by equation (1). In this case, V= V,: sunrival wind velocity. d) Remove the sand bags. e) Install the antenna under test as indicate
20、d in figure 2c and apply force W2 to the primary radiator. The value of W2 is given by equation (2). In this case, V= V,: survival wind velocity. f) Remove force W2. STD-BSI BS EN bLLLLI-2-ENGL L797 m Lb2LibbS Ob25170 O72 m Page 10 EN 61114-2 : 1996 Vibration frequency range HZ Amplitude mm Sweep cy
21、cle (5-55-5 Hz) Sweep mode Direction of vibration 1 Test duration g) Measure the antenna gain or G/T and compare it with the gain or G/T measured in a). h) Measure the gain or G/T of a new sample of the same type as the antenna under test. i) Install the antenna under test on a rigid antenna fixture
22、 at its centre part, and position the aperture horizontally and downwardas shown in figure 2b. j) Follow the same procedure as shown from c) to f). k) Measure the antenna gain or GTT and compare it with the gain or G/T measured in h). NOTE - See note of 5.1.1. 5-1 O 10-20 20-55 1.5 1 .o 0.5 10 min L
23、ogarithmic or linear approximation Vedcal, longitudinal and transversal 2 h for each direction 5.2.2 Presentation of results The results shall be listed in a table. An example of the table is shown in 5.1.2. NOTE - See note of 5.1.2. 5.3 Wind load at destructive wind velocity 5.3.1 Method of measure
24、ment lhe measurement procedure is the same as for 5.2.1, except that V is vd (destructive wind velocity) and the gain or G/T measurement is not performed. Then, visually inspect the effects on the antenna under test and note if the mechanical integrity is preserved or not. 5.3.2 Presentation of resu
25、lts The results shall be listed in a table. An example of the table is shown in 5.1.2. 5.4 Vibration test 5.4.1 Test conditions Test conditions are shown in table 4. STD.BS1 BS EN bLLL9-2-ENGL 1977 1b24bb7 Ob25171 TO9 Page 11 EN 61114-2 : 1996 5.4.2 Method of measuremeni a) Measure the gain or GTT o
26、f the antenna under test. b) Rigidly mount the antenna under test, assembled together with its supporting structure in accordance with an installation manual prepared by a manufacturer, to a vibration table. The antenna shall have the same configuration as when it is used for operation. The antenna
27、supporting mast shall be as short as possible and mounted rigidly. The test equipment arrangement is shown in figure 3. An elevation angle of the antenna under test shall be chosen from the values given in the standard of the country for which the antenna is designed. c) Vibration shall be sequentia
28、lly applied in vertical, in longitudinal and in transversal directions. d) Visually inspect the antenna under test for possible mechanical changes such as loose screws, cracks or parts distortion. If no degradation is observed, detach the antenna under test and measure the antenna gain or G/T. e) Co
29、mpare the gain or GK with the gain or GK measured in a). NOTE - See note of 5.1 .l. 5.4.3 Presentation of results The results shall be listed in a table. An example of the table is shown in 5.1.2. NOTE - See note of 8.1.2. 5.5 Durability test at mechanical resonant frequency 5.5.1 Test conditions Th
30、e test conditions are given in table 5. Table 5 - Test conditione for vibration test (mechanical resonant frequency) Direction Vertical, longitudinal and transversal 5.5.2 Method of measurement a) Measure the gain or G/T of the antenna under test. b) Install the antenna under test rigidly to the cen
31、tre of the vibration table. c) Apply the vibration vertically, and sweep the vibration frequency from 5 Ht to 100 Hz. The acceleration shall have an amplitude of 0,5 9. The frequency should be swept slowly so that accurate measurement can be made. d) Note the frequencies that give maximum accelerati
32、on at the following six points: - antenna fixture to a supporting mast: - primary radiator fixture to its supporting structure; - upper edge of the reflector; - lower edge of the reflector; - right side edge of the reflector; - left side edge of the reflector. . STD*BSI BS EN bLL14-2-ENGL 1777 LbZib
33、b7 Ob25172 745 W Page 12 EN 61114-2 : 1996 e) Repeat c) to d) but in longitudinal and in transversal directions. f) Apply the vibration according to table 5 to the antenna under test at the 18 resonant frequencies obtained in c) to e). g) Visually inspect the antenna under test for possible mechanic
34、l changes such as loose screws, cracks or parts distortion. If no degradation is observed, detach the antenna under test and measure the antenna gain or G/T. h) Compare the gain or G/T with the gain or G/T measured in a). NOTE -See note of 5.1.1. 5.5.3 Presentation of results The results shall be li
35、sted in a table. An example of the table is shown in 5.1.2. NOTE - See note of 5.1.2. 5.6 Impact test 5.6.1 Test conditions The test conditions are given in table 6. Table 6 - Test conditions for impact test Direction Vertical, longitudinal and transversal 5.6.2 Method of measurement a) Measure the
36、gain or GTT of the antenna under test. b) Install the antenna under test on a rotatable wooden board, as shown in figure 4, which is connected to a horizontal concrete floor with a hinge at one edge. The board thickness shall be greater than 42 mm. The board length shall be greater than the maximum
37、dimension of the reflector. The antenna under test shall have the same configuration as when it is operating. The antenna supporting mast shall be as short as possible and mounted rigidly. An elevation angle of the antenna under test shall be chosen from the values given in the standard of the count
38、ry for which the antenna is designed. c) Measure impact acceleration by means of an acceleration meter attached near the antenna mount. Determine a lift height that gives an acceleration specified in table 6, to the antenna under test. d) Lift the board to the lift height and release it. e) Repeat d
39、). The number of times is given in table 6. f) If no change is observed by visual inspection, detach the antenna under test and measure the antenna gain or G/T. g) Compare the gain or G/T with the gain or G/T measured in a). h) Repeat a) to g) for other impact directions. NOTE - See note of 5.1.1. *
40、 * rn STD-BSI BS EN bLLLY-2-ENGL 1777 1b24bb7 Ob25173 L Page 13 EN 61114-2 : 1996 5.6.3 Presentation of results The results shall be listed in a table. An example of the table is shown in 5.1.2. NOTE - See note of 5.1.2. 5.7 Heat cycle test 5.7.1 Methods of measurement a) Measure the gain or GTT of
41、the antenna under test. b) Place the antenna under test in the test chamber with the same structure as that used when in operation. c) Apply the heat cycle shown in figure 5, repeating the cycle continuously five times. d) Leave the antenna for 4 h at normal temperature and humidity. e) If no change
42、 is observed by visual inspection, measure the antenna gain or G/T. 9 Compare the gain or OTT with the gain or GTT measured in a). NOTE - See note of 5.1.1. 5.7.2 Presentation of results The results shall be listed in a table. An example of the table is shown in 5.1.2. NOTE - See note of 5.1.2. 5.8
43、Solar radiation exposure test 5.8.1 introduction This test evaluates the effect of solar radiation exposure by measuring the temperature increment inside the electronic apparatus (.e. the SHF converter) located in the primary focus of a paraboloidal reflector antenna, when the sun is aligned with th
44、e main axis of the radiation diagram of the antenna. If a Cassegrain mounting is used on the antenna, the temperature increment is also evaluated in the place where the SHF converter is located. . The measurement shall be carried out during the hours of maximum solar radiation (around . solar noon)
45、and when the sky is clear and no clouds are covering the sun. Otherwise the effect of the reduced atmosphere transparency due to clouds has to be taken into account using a reference paraboloidal reflector antenna, whose temperature increment in the primary focus in clear sky conditions is well know
46、n. Careful attention shall be paid to avoid the influence of ambient factors like wind, whose speed must not exceed 0.5 m/s (1,8 km/h). Because the temperature increment depends also on the latitude of the place where the antenna is installed and on the period of the year in which the measurement is
47、 performed, a correction factor shall be introduced to obtain comparable results. - STD-BSI BS EN bLL14-2-ENGL 1997 m Lb24bb9 Ob25174 718 m Page 14 EN 61114-2 : 1996 5.8.2 Method of measurement a) Connect a suitable thermometer (e.g. a thermocouple) to the SHF converter in such a way that the inside
48、 temperature is measured. NOTE - In some cases, if the SHF converter is sealed (waterproofed), a hole should be made on the cover of the apparatus in order to measure the inside temperature. b) Apply the d.c. supply to the SHF converter as prescribed by the manufacturer (e.g. through the r.f. output
49、 cable), using a suitable d.c. power supply. c) The antenna under test is first pointed towards a point of the sky opposite in azimuth to that of the sun and left in such position for a sufficient time until a stable temperature reading is obtained. This temperature is recorded as Ti. d) The antenna under test is then pointed towards the sun, reading at the same time the inside temperature of the SHF converter located in the primary focus of the antenna under test or in other positions (ag. Cassegrain mounting). The temperature value is recorded in a suitable
