Upload
tiffany-cobb
View
224
Download
1
Tags:
Embed Size (px)
Citation preview
Device Development for NASA Space Communications
Novel Power Combiner for Solid State Power Amplifiers
Andrew AbrahamEdwin Wintucky
Communications, Instrumentation, & ControlsElectron & Opto-Electron Device Branch
July 9, 2009
Why Use Microwaves?
• Provides good bandwidth• FCC allocated 30GHz for Deep Space
– Some attenuation from atmosphere
30 GHz
100 MHz
Microwave
Radio
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
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
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
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
Step 1: S-Matrix Parameters• Network Analyzer
• S-Matrix enables efficiency predictions
S-MatrixInbound Signal
Outbound Signal
Step 2: Construct a 3-Way Circuit
Preliminary Data
Ou
tpu
t P
ort
(N
orm
aliz
ed)
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
Questions