1. Meteor Receiver Olajide Durosinmi Hugh Kinsel Kenny Mills Austin Pierce Nick Stelmashenko October 21, 2009

2. 2 Meteor Receiver Overview Receives radio signals reflected off of objects in the Earth’s atmosphere Provides sound when space object is detected Approximates direction and estimated speed of space objects Targets astronomy enthusiasts Costs $250 for prototype Antenna Receiver Ionized Meteor Trail

3. 3 Meteor Receiver Objectives Hardware Receives a specific radio frequency Filters and amplifies the given frequency Reduces the amplified signal to baseband Converts the signal from analog to digital for analysis Software Collects and stores the digital data from the hardware Detects passing of a space object Outputs audible signal Determines the direction and speed of the objects

4. 4 Target Transmitter Frequency: 216.983 MHz Naval Space Surveillance(NAVSPASUR) transmitter located in Texas Most powerful continuous wave transmitter on Earth All circuit components based on 217 MHz Lake Kickapoo, Texas Atlanta, Georgia

5. 5 Receiver Module Antennas in Phased Array Local Oscillator Demodulator Analog to Digital Conversion Filter and Low Noise Amplifiers

6. 6 Receiver Module Local Oscillator Demodulator Analog to Digital Conversion Antenna

7. 7 Yagi Dimensions Optimized for 217 MHz Symbol - Description Length (λ)Length (m) L 1 - Reflector0.4870.673 L 2 - Feed (Driver)0.4750.656 L 2 ' - Gamma match0.1450.2 L 3 - Director0.410.567 S 01 - Space between rear & L 1 0.2170.3 S 12 - Space between L 1 & L 2 0.20.276 S 23 - Space between L 2 & L 3 0.230.318 D 1 - Diameter of elements 0.009190.0127 D 2 - Diameter of Gamma match 0.004590.00635

8. 8 Estimated Antenna Specifications Simulated by NEC2 and Method of Moments MATLAB Code Number of elements3 Center frequency (Fc)217 MHz Gain9.2 dBd (11.35 dBi) -3 dB beamwidth in the E-plane 58.88° -3 dB beamwidth in the H-plane 75.18° Front-to-back ratio in the E-Plane 12.1 dB Impedance before match35.2 + j14.2 Impedance after match50 Ω

9. 9 Link Budget: Reason for Amplification P r (d) = P t G t G r σλ 2 (4π) 2 d 4 Example Case: International Space Station P r = (767 kW)(10 4 )(10 0.92 )(100 m 2 )(1.382 m) 2 (4π) 2 (1000 km) 4 ≈ 7.7 x 10 -14 W = -101 dBm Radar equation used to estimate signal’s power level Multiple stages of amplification needed

10. 10 Filter and Low Noise Amplifiers Receiver Module Antennas in Phased Array Local Oscillator Demodulator Analog to Digital Conversion

11. 11 Filter and Low Noise Amplifier(LNA) Filter designed with inductors and capacitors circuit Desired frequency centered in a narrow bandwidth Impedance of the filter is 50Ω (matching) MGA62563 LNA from Avago Technologies Cascading 2 LNA devices on a PCB to increase the gain, A v Expected gain, A v from LNA is 44dB

12. 12 Filter and LNA unit Direct current (DC) blocking to limit DC flow Matching pads to reduce degrading of the signal Radio Frequency (RF) choke to limit RF noise Expected overall gain, A v, of unit is approximately 30dB LNA Power

13. 13 Filter and Low Noise Amplifiers Receiver Module Antennas in Phased Array Local Oscillator Demodulator Analog to Digital Conversion

14. 14 Local Oscillator Design PurposeProvide a reference signal for the receiver module Design Frequency434 MHz (217MHz x 2) Design ConsiderationsLow noise, Programmable Design ChoiceADF7012 Current ProgressPCB designed, PCB and parts ordered and received

15. 15 Filter and Low Noise Amplifiers Receiver Module Antennas in Phased Array Local Oscillator Demodulator Analog to Digital Conversion

16. 16 Receiver Module Design PurposeReduce the signal to baseband, Amplify the signal for DAQ Design ConsiderationsLow noise, Q and I outputs, Programmable gain Design ChoiceAD8348 Inputs434 MHz from oscillator, Amplified signal from LNAs OutputsQ and I components of the mixed inputs Current ProgressPreliminary PCB designed

17. 17 Filter and Low Noise Amplifiers Receiver Module Antennas in Phased Array Local Oscillator Demodulator Analog to Digital Conversion

18. 18 Data Acquisition NI USB-6251 –16 analog inputs (1 MS/s) –2 analog outputs –24 digital I/O –Signal Conditioning MATLAB Data Acquisition Toolbox –Control outputs for variable gain amplifiers –Store data in MATLAB for processing

19. 19 Line showing presence of CW transmitter Data Processing Audacity –Digital Audio Editor –Quick Spectrum MATLAB –Signal detection using STFT (Short-Time Fourier Transform) –Spectrogram –Estimate objects’ speed

20. 20 Filter and Low Noise Amplifiers Receiver Module Antennas in Phased Array Local Oscillator Demodulator Analog to Digital Conversion

21. 21 Phased Array Purpose: –Direction of arrival estimation –Signal strength increase Four antennas/channels –Identical hardware Processing with MATLAB –Phase comparison in two planes –Possibility of imaging

22. 22 Demonstration Plan Set up system components –Antennas, primary enclosure, laptop Listen for and successfully intercept echo from space object –Satellite, not meteor, due to predictability Process data –Calculate direction, position, radial velocity –Present results to operators in real time Location: ECE rooftop

23. 23 Project Schedule Test Local Oscillator circuit boardOctober 23 rd Order Receiver board and componentsOctober 23 rd Order LNA board and componentsOctober 29 th Test single system (Antenna to DAQ)November 10 th Assemble additional systemsNovember 15 th Collect data for Matlab analysisNovember 20 th

24. 24 Current Status of Project Antenna prototype undergoing evaluation LNA and Filter design in progress Local oscillator ready for assembly and testing Receiver module designed Development of MATLAB software initiated

25. 25 Questions?

26. 26 Local Oscillator

27. 27 Local Oscillator

28. 28 Demodulator

29. 29 Demodulator

30. 30 Demodulator

31. 31 Demodulator