Device Development for NASA Space Communications Novel Power Combiner for Solid State Power Amplifiers

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Device Development for NASA Space Communications
Novel Power Combiner for Solid State Power
Amplifiers

• Andrew Abraham
• Edwin Wintucky
• Communications, Instrumentation, Controls
• Electron Opto-Electron Device Branch
• July 9, 2009

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Why Use Microwaves?

• Provides good bandwidth
• FCC allocated 30GHz for Deep Space
• Some attenuation from atmosphere

30 GHz
Microwave
100 MHz
Radio
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The Need for Space-Based Microwave Communication

• Moon to Earth Communications
• Crew Exploration Vehicle
• Lunar Lander, Lunar Outpost
• Lunar Relay Satellite
• Moon to LEO Communications
• Moon to ISS communication
• Moon to Tracking Data Relay Satellite System
  (TDRSS)
• Deep Space to Earth Communications
• Manned/Unmanned Missions to Mars
• Missions to the outer planets

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Power Requirements For Space-Based Microwave
Communications

• Inverse square law
• Mandates 10-15W of power for deep space missions
• Limitations on SSPAs (Solid State Power
  Amplifier)
• One SSPA can get up to 5-6W

Typical SSPA
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How to Increase Power

• Approach 1 Engineer more powerful SSPAs
• Problem Inefficiency (Heat)
• Approach 2 Combine multiple SSPAs
• Create a microwave power combiner
• 3-way power combining is necessary for current
  SSPA technology

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Project Goals

• Design and construct testing circuitry to
  evaluate the performance of
• Novel 3-Way Rectangular Waveguide Hybrid
  Combiner
• Characterize the hybrid combiner
• S-Parameters
• Efficiency
• Frequency Response
• Phasing

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Step 1 S-Matrix Parameters

• Network Analyzer
• S-Matrix enables efficiency predictions

Inbound Signal
Outbound Signal
S-Matrix
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Step 2 Construct a 3-Way Circuit
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Preliminary Data
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Planned Activities

• Measure efficiency of 3-way combiner
• Quantify frequency response
• Measure and compare other combining methods
• Multiple 2-way power combiners
• Multiple Magic-T hybrid couplers
• Mix of Magic-T and power combiners

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Questions