Automated Antenna Controller. Our Team Sam Bryan – Team Leader Electrical Engineer Hardware...
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Transcript of Automated Antenna Controller. Our Team Sam Bryan – Team Leader Electrical Engineer Hardware...
Automated Antenna ControllerAutomated Antenna Controller
Our TeamOur Team
Sam Bryan – Team LeaderSam Bryan – Team LeaderElectrical EngineerElectrical Engineer
Hardware PrototypingHardware PrototypingLCD CommunicationLCD Communication
Brandon Gray Brandon Gray Electrical EngineerElectrical Engineer
Hardware PrototypingHardware PrototypingFrequency Counting Frequency Counting
Jacob EdwardsJacob EdwardsComputer EngineerComputer Engineer
Microprocessor Microprocessor ProgrammingProgramming
Ashley StoughAshley StoughElectrical EngineerElectrical Engineer
LCD CommunicationLCD CommunicationFrequency CountingFrequency Counting
Dr. Raymond WintonDr. Raymond WintonAcademic AdvisorAcademic Advisor
SponsorSponsor
OutlineOutline• IntroductionIntroduction• ProblemProblem• SolutionSolution• ConstraintsConstraints
– TechnicalTechnical– PracticalPractical
• Special ConcernsSpecial Concerns– ManufacturabilityManufacturability– Health and SafetyHealth and Safety
• System Overview System Overview • ProgressProgress• TimelineTimeline• QuestionsQuestions
What is the Automated Antenna What is the Automated Antenna Controller?Controller?
– Microprocessor controlled version of MFJ Microprocessor controlled version of MFJ Enterprises, Inc.’s user-managed loop Enterprises, Inc.’s user-managed loop antenna controller antenna controller
– Used with MFJ-1786 and MFJ-1788 Super Used with MFJ-1786 and MFJ-1788 Super Hi-Q Loop Antennas Hi-Q Loop Antennas
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What is the Automated Antenna What is the Automated Antenna Controller?Controller? (cont’d) (cont’d)
• Unit controls a motor attached to a variable plate capacitor Unit controls a motor attached to a variable plate capacitor which adds capacitance to the impedance of the loadwhich adds capacitance to the impedance of the load
• Standing Wave Ratio (SWR)Standing Wave Ratio (SWR)– Ratio of power or impedance: Ratio of power or impedance:
• Power reflected to source versus power transmitted Power reflected to source versus power transmitted from sourcefrom source
• Load impedance against source impedanceLoad impedance against source impedance
Problems with Existing ControllerProblems with Existing Controller
• Operation is Time ConsumingOperation is Time Consuming• Unit is Difficult to OperateUnit is Difficult to Operate• Meter is Difficult to Read AccuratelyMeter is Difficult to Read Accurately• Inaccurately controlledInaccurately controlled
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SolutionSolution
• Use microcontroller to allow more accurate Use microcontroller to allow more accurate tuningtuning
• Automate the tuning process to avoid user Automate the tuning process to avoid user errorerror
• Utilize digital display to allow easier output Utilize digital display to allow easier output for userfor user
Technical ConstraintsTechnical ConstraintsNameName ConstraintConstraintFrequencyFrequency Frequency must measure and display between 7 and Frequency must measure and display between 7 and
30MHz ± 30kHz. 30MHz ± 30kHz.
Standing Wave RatioStanding Wave Ratio A maximum of 3:1 SWR must be achieved.A maximum of 3:1 SWR must be achieved.
ConnectorConnector RF connection must be an SO-239 style connector. RF connection must be an SO-239 style connector.
RF PowerRF Power Forward and reflected power must be measured and Forward and reflected power must be measured and displayed accurately to ± 1W. displayed accurately to ± 1W.
Power SupplyPower Supply Power supply must be the MFJ-1312D AC adapter.Power supply must be the MFJ-1312D AC adapter.
Manufacturability: SizeManufacturability: Size• Large enough to accommodate analog and Large enough to accommodate analog and
digital displaysdigital displays• Within reason from previous model Within reason from previous model • Suggested Size: 4in x 7in x 7in. Suggested Size: 4in x 7in x 7in.
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Health and SafetyHealth and Safety
• Enclose the controllerEnclose the controller– Prevent electric shockPrevent electric shock– Prevent burns from hot componentsPrevent burns from hot components– Prevent RF burnsPrevent RF burns
System OverviewSystem Overview
MicrocontrollerMicrocontroller
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Previous Experience
Available from Manufacturer
PWM Ports Price
PIC 16 0 members Yes 1 $2.97
PIC 18F2520
4 members Yes 2 $3.98
LCD LCD
Backlight Supplied by Manufacturer
Price
WH-1602B-NGB
No Yes 10.40
WH-1602B-GGE
Yes, Green
Yes 10.40
SWR MeasurementSWR Measurement
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IndirectIndirect
DirectDirect
SWR Measurement (cont’d)SWR Measurement (cont’d)
Effect on transmission line
Frequency dependency
Output
Indirect None Independent Representative voltage
Direct Introduces impedance
Dependent Representative voltage
TimelineTimeline
Month August September October November
Research
Hardware Prototyping
Programming
Testing
Operational Prototype
ProgressProgress• PrototypingPrototyping• TestingTesting
PrototypingPrototyping
TestingTesting
Testing (cont’d)Testing (cont’d)
0
5
10
15
20
25
30
7.500 10.000 15.000 17.647 20.000 25.000 30.000
Frequency (MHz)
Stan
ding
Wav
e Ra
tio
Low Power
10 W
40 W
70 W
100 W
SummarySummary• ProblemProblem• SolutionSolution• ConstraintsConstraints
– TechnicalTechnical– PracticalPractical
• Special ConcernsSpecial Concerns– ManufacturabilityManufacturability– Health and SafetyHealth and Safety
• System Overview System Overview • Trade-offsTrade-offs• TimelineTimeline• ProgressProgress
References References [1]http://www.mfjenterprises.com/Product.php?productid=MFJ-1786.[1]http://www.mfjenterprises.com/Product.php?productid=MFJ-1786.
[Online]. Accessed: September 29, 2009.[Online]. Accessed: September 29, 2009.[2]http://www.mfjenterprises.com/catalog/Pages_061-080.pdf [Online]. [2]http://www.mfjenterprises.com/catalog/Pages_061-080.pdf [Online].
Accessed: September 27, 2009.Accessed: September 27, 2009.[3]MFJ Enterprises, INC., [3]MFJ Enterprises, INC., MFJ Super Hi-Q Loop Antenna: Model MFJ MFJ Super Hi-Q Loop Antenna: Model MFJ
1786/1788 Instruction Manual1786/1788 Instruction Manual, 1997., 1997.[4]http://media.digikey.com/photos/Microchip%20Tech%20Photos/[4]http://media.digikey.com/photos/Microchip%20Tech%20Photos/
pic18f2520-i%20sp.JPG. [Online]. Accessed: September 30, 2009. pic18f2520-i%20sp.JPG. [Online]. Accessed: September 30, 2009. [5] “PIC18F2420/2520/4420/4520 Datasheet”, 2008. Microchip [5] “PIC18F2420/2520/4420/4520 Datasheet”, 2008. Microchip
Technology Inc. pg 326.Technology Inc. pg 326.[6]http://vk1od.net/transmissionline/VSWR/VSWRMeter.htm. Owen [6]http://vk1od.net/transmissionline/VSWR/VSWRMeter.htm. Owen
Duffy 1995, 2006Duffy 1995, 2006 [Online]. Accessed: October 6, 2009.[Online]. Accessed: October 6, 2009.[7] http://ludens.cl/Electron/swr/swr.html [Online]. Accessed: October 6, [7] http://ludens.cl/Electron/swr/swr.html [Online]. Accessed: October 6,
2009.2009.
Questions?Questions?