Techniques to Optimize Usage of Satellite RF Power X.T. Vuong, VP and Chief Scientist Artel, LLC, Herndon, Virginia, xvuong@artelllc.com X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 1
Transponder Power Usage Optimization Power Efficient Modulation and FEC Coding e.g., {QPSK, ½ LDPC} At Expense of BW Utilization Transponder Set with High PAD Attenuation i.e., Low Gain At Expense of High EIRP from Transmit Earth Station Receive Earth Station with High G/T i.e., Large Receive Earth Station X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 2
Conventional Satellite Payload RF Power Utilization Problem Under Utilization of Available RF Power on One Transponder (Channel or Downlink Beam) Waste of Available RF Power Over Utilization of Available RF Power on One Transponder (Channel or Downlink Beam) Denial of Services Link Eb/No Degradation X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 3
Solution to Under/Over Utilization Problem: Satellite Payload w/ ATPA or MARS ATPA: Active Transmit Phase Array MARS: Matrix Amplifier and Routing System Available RF Power from HPAs (SSPAs ortwtas) Automatically Pooled Together and Shared. ATPA Capable of Shaping and Steering Beams MARS Capable of Routing Signals w/o Using Switches (After HPAs). X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 4
ATPA (Active Transmit Phase Array) Iridium (S Band, 1997), Spaceway (Ka Band, 2007) Exhibit II.1: General ATPA Block Diagram X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 5
Exhibit II.2: General BFM Block Diagram X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 6
Analogous to Spectral Regrowth Exhibit II.5: Two Dimensional Gain Pattern (Azimuth Cut) of ATPA Versus EIPBO. Case 2 (Single Beam, Unequal Beam Weight Magnitudes) with Ten Equal Power Carriers. X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 7
Exhibit II.4: Spatial Gain Pattern of ATPA Versus EIPBO. Case 2 (Single Beam, Unequal Beam Weight Magnitudes) with Ten Equal Power Carriers. X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 8
Exhibit II.6: Spatial Pattern of (2A B) IMP EIRP of ATPA Versus EIPBO. Case 2 (Single Beam, Unequal Beam Weight Magnitudes) with Ten Equal Power Carriers X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 9
Analogous to Spectral IM Locations and More Exhibit II.9: Spatial Locations of the Six 3 rd Order IM Beams. Case 3 (Two Beams, Equal Beam Weight Magnitudes) w/ Two Equal Power Carriers Per Beam X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 10
MARS (Matrix Amplifier and Routing System) Power Sharing Only: Butler Transponder Hybrid Amplifier Hybrid Transponder Matrix Amplifier Matrix Transponder Multi Port Amplifier Multi Port Transponder X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 11
Inmarsat 3 (L Band, 1995) and AMSC/TMI's MSAT (L Band, 1995), ETS 6 (S Band,1996) and E172B (Ku Band, 2017) Exhibit III.1: General MARS Block Diagram X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 12
Exhibit III.2: Recursive Definition of General Hybrid Matrix G(KxK) X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 13
Exhibit III.4: Hybrid Matrix S(KxK) Family K = 2, 4, 8, and 16. X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 14
Figure 5: Different Realization of Power Sharing Only MARS X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 15
Routing Vector: Phase Shifter Values Associated w. an Input Port. Exhibit III.5: Input Matrix of Flexible Routing MARS. X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 16
Some Routing Capability and Characterstics Exhibit III.6: Routing Results for (MxKxK) MARS for K = 2 and 4 with 2 Bit Phase Shifters. X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 17
Inter Port Intermodulation Products (IMPs) Characteristics Output Port Destination of (2A B) = Output Port Destination of B Output Port Destination of (A + B C) = Output Port Destination of A If B & C Have Same Output Port Destination Output Port Destination of (A + B C) = Output Port Destination of C If A & B Have Same Output Port Destination X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 18
Output Port #4: (1 6 7) Carrier A: Destined to OP Port #1 Carrier B: Destined to OP Port #6 Carrier C: Destined to OP Port #7 (A + B C) IMP: Destined to OP Port #4 A + B C 2A B Exhibit III.7: Output Port Destinations of Inter Port Third Order (A+B C) and (2A B) IMPs One to One Routing MARS with Hybrid Matrix G(8x8) As Output Matrix X.T. Vuong: Techniques to Optimize Usage of Satellite RF Power Page 19