Meteor Receiver Andrew Thoni Charlie Hunter Greg Watkins Nick Nicholson Will Marshall
Jan 17, 2016
Meteor ReceiverMeteor Receiver
Andrew ThoniCharlie HunterGreg Watkins
Nick NicholsonWill Marshall
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Project OverviewProject Overview
• Design a receiver to detect objects in orbit passing through the NAVSPASUR.
• There is a community of hobbyist who want to detect space objects.
• Dr. Smith is extremely interested in owning one of these systems for a personal hobby.
• Total cost estimate is $360
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Design ObjectivesDesign Objectives
Objective Achieved
Receive 217MHz with antennas Yes
Demodulate input signal to the audio band.
Yes
Output the antenna signal to a computer for storage.
Yes
Playback the signal as audio. Yes
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Illustration of DesignIllustration of Design
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Simulated Antenna ImpedanceSimulated Antenna Impedance
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Simulated Antenna GainSimulated Antenna Gain
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Measured Antenna GainMeasured Antenna Gain
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Simulated Antenna 3D Gain at 217 MHzSimulated Antenna 3D Gain at 217 MHz
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Measured Antenna Beam WidthMeasured Antenna Beam Width
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Antenna ProblemsAntenna Problems
• Antenna design is 75 Ω but the testing equipment is 50 Ω
• Mechanical solution for attaching a connector
• Optimal spacing between the two dipole sides
• Directivity is too low.
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Antenna SolutionsAntenna Solutions
• BNC 75 Ω to 50 Ω transformer to connect to the network analyzer
• Spade lugs and hose clamps to connect the cable to the driven element
• Dipole spacing was not an issue• Redesign and add matching network to
increase directivity
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Amplifier DesignAmplifier Design
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Amplifier Problems and SolutionAmplifier Problems and Solution
• Problems– Capacitors were too short for gaps in the
board.– Soldering was not done well.– All the boards were shorted out.
• Solution– Use commercial amplifiers.
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Commercial AmplifierCommercial Amplifier
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Demodulator CircuitDemodulator Circuit
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Demodulator Amplifier TestingDemodulator Amplifier Testing
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Demodulation with 217.02 MHz InputDemodulation with 217.02 MHz Input
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PC Control and Capture TestingPC Control and Capture Testing
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PC Control and Capture ProblemsPC Control and Capture Problems
• Problems– Two ports are XLR connectors– Unable to consistently write to DAC
• Solutions– Proposed XLR to RCA adapter– DAC defaults to maximum gain
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Control and Capture Problems ContinuedControl and Capture Problems Continued
• Problems– Defective buffer– Able to write to LO, but unable to generate
desired frequency• Solutions
– Bypass buffer– External frequency source
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PCB ProblemsPCB Problems
• Coax input through-hole pads too small• DB-25 connector does not fit• Voltage regulator pins reversed• Buffer chip enables tied to disabled position• RCA outputs blocked by other components• Option for external oscillator not included
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Future WorkFuture Work
• Perfect Low Noise Amplifier design.• Capture data with PC.• Complete software package to display
position and velocity of space objects.
Meteor ReceiverMeteor Receiver
Andrew ThoniCharlie HunterGreg WatikinsNick NicholsonWill Marshall