Fig 5-Choked flanges used for PIM test at L-band Table 1-PIM test parameter ample dime WR650 025x025 025x025 for carrier(dBm】 120 109 107 equency carrier 1(GHz) quency carrier 2(GHz) PIM frequency (GHz) 162 3.97 142 xfeed-sample distance (m) T6Rx65 Tx 18S.Bx 196 Noise floor (dBm) -150 -135 -140 Test mode Conducted Radiated Radiated KU-BAND TEST RESULTS PIM as function of power of carriers be3-dB per dB PIM as function of mesh tension -dBm.Th agegwcem5a8emiemNwnei6eem比E from 25 to60 grams/cm.The minimum PIM power level (-132-dBm)wa cted for a arou PIM as function of micro-vibrations f the satellite local deforma tion of the mes Ise every 5 Fig. 5-Choked flanges used for PIM test at L-band Table 1-PIM test parameters Frequency band L C Ku Sample dimensions (m) WR650 0.25 x 0.25 0.25 x 0.25 Power level for carrier (dBm) 37 50 50 Equiv. PIM requirement on samp le (dBm) -130 -105 -102 Frequency carrier 1 (GHz) 1.53 3.49 10.95 Frequency carrier 2 (GHz) 1.56 3.65 12.60 PIM order 5 5 3 PIM frequency (GHz) 1.62 3.97 14.25 Tx/Rx feed-sample distance (m) - 0.25 0.70 Horn Gain (dBi) - Tx: 6-Rx: 6.5 Tx: 18.5-Rx: 19.6 Noise floor (dBm) -150 -135 -140 Test mode Conducted Radiated Radiated KU-BAND TEST RESULTS PIM as function of power of carriers Fig. 6 gives the results for the change in PIM power level received for a change in the input power of the carriers. The tension on the mesh was settled at 5 grams/cm and the test distance was 0.7-m. The PIM roll-off (3rd order) was found to be 3-dB per dB. PIM as function of mesh tension Fig. 7 gives the PIM power level as function of the mesh tension. The power of the carriers was fixed at 50-dBm. The measured PIM power level was below the required specification value (-102-dBm) for mesh tension values ranging from 2.5 to 60 grams/cm. The minimum PIM power level (-132-dBm) was detected for a mesh tension of 40 grams/cm. In the antenna operative range of tensions (between 5 and 8 grams/cm) the PIM power level can be assumed constant around -122-dBm. PIM as function of micro-vibrations Micro-vibrations can be indicative of attitude manoeuvres of the satellite. Local deformation of the mesh was generated by a pulsating stream of clean air (1 pulse every 5 second) directed to the centre of the sample. The out of plane deformation was 3-mm in the centre of the mesh. When the micro-vibrations effects are taken into account, the PIM power levels experienced are above the required specification value (max-detected value was -82-dBm)