QCVN 99:2015/BTTTT Measurement procedures are as follows: Prepare the measurement location selected from Appendix B. Initial arrangement of OBU as a necessary condition in step 4 must be based on the direction M0 as shown in Figure 2, which means the axial direction of OBU must be directed right to the center part of the test antenna. Figure 2 The directions Mi of OBU – Turn on the monochromatic output signal of MSS1, adjust to the frequency fTx determined for channel 1 (see Table 6). Adjust output power of MSS1 so that PRSA is measured by a power meter PM1 which is equivalent to the value: PRSA = Pinc x GRSA x ( ) Replace RSA by OBU so that the phase center Mc of OBU coincides more and more with the rotation axis of turntable as possible. If not knowing the phase center Mc of OBU and there is no visible antenna, the center of OBU will be selected for replacement. Adjust the axial direction of OBU as required. Set OBU into the test mode so that OBU plays back the test signal TS2 with the subcarrier frequency fs. Measure the greater value of the power level Pmax in two bands from the receiving equipment, use the value of range bandwidth 100 kHz and record the value Pmax along with the direction of OBU Mi (i = 0,1,2,3,4) and the value of fs and fTx (i = 0,1,2 , 3.4) Repeat step 6 for other values of the subcarrier frequency fs. Repeat steps 3 through 7 for the center frequency fTx determined for channel 4 according to Table 6. If OBU is type B, continue to step 10, otherwise skip to step 11. Repeat step 1 to step 8 for all remaining OBU directions indicated by M1, M2, M3, and M4 in Figure 2 to determine the parameter U4a. Replace OBU by the sub-antenna TSA calibrated to left hand circular polarization with the gain GTSA and reflectivity at the antenna connector in conformity with the space of center frequency fTx listed in Table 6 so that the antenna phase center coincides with the phase 24
QCVN 99:2015/BTTTT Measurement procedures are as follows: Prepare the measurement location selected from Appendix B. Initial arrangement of OBU as a necessary condition in step 4 must be based on the direction M0 as shown in Figure 2, which means the axial direction of OBU must be directed right to the center part of the test antenna. Figure 2 – The directions Mi of OBU Turn on the monochromatic output signal of MSS1, adjust to the frequency fTx determined for channel 1 (see Table 6). Adjust output power of MSS1 so that PRSA is measured by a power meter PM1 which is equivalent to the value: PRSA = Pinc x GRSA x ( ) Replace RSA by OBU so that the phase center Mc of OBU coincides more and more with the rotation axis of turntable as possible. If not knowing the phase center Mc of OBU and there is no visible antenna, the center of OBU will be selected for replacement. Adjust the axial direction of OBU as required. Set OBU into the test mode so that OBU plays back the test signal TS2 with the subcarrier frequency fs. Measure the greater value of the power level Pmax in two bands from the receiving equipment, use the value of range bandwidth 100 kHz and record the value Pmax along with the direction of OBU Mi (i = 0,1,2,3,4) and the value of fs and fTx (i = 0,1,2 , 3.4) Repeat step 6 for other values of the subcarrier frequency fs. Repeat steps 3 through 7 for the center frequency fTx determined for channel 4 according to Table 6. If OBU is type B, continue to step 10, otherwise skip to step 11. Repeat step 1 to step 8 for all remaining OBU directions indicated by M1, M2, M3, and M4 in Figure 2 to determine the parameter U4a. Replace OBU by the sub-antenna TSA calibrated to left hand circular polarization with the gain GTSA and reflectivity at the antenna connector in conformity with the space of center frequency fTx listed in Table 6 so that the antenna phase center coincides with the phase 24
QCVN-99-thiet-bi-vo-tuyen--toc-do-TB.DOCX