Download RF Power Level Capturing System - Senior Design

RF Power Level Capturing System
Project Proposal
Team Number: May 04-27
Date Submitted: 23rd September 2003
Client:
Jim Mitchell
Rockwell Collins, Inc.
MS 108-25
400 Collins Road NE
Cedar Rapids, IA 52498
Ph: 319-295-2031
Fax: 319-295-8823
Team Members:
Faculty Advisor:
Tausif Awan
Abdul Basit
Ahmed Mir
Fazal Haq
Dr Steve Russell, P.E
2427 Coover Hall
Iowa State University
Ames, IA 50014
Ph: 515-294-1273
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Table of Contents:
Table of Contents. ………………………………………………………………………...2
List of Figures …………………………………………….………….……...……………3
List of Tables ……………………………….………………………….………………….3
Definition of Terms………………………………………………………………………..4
Acknowledgement ……………………………………………..…………………...…….4
Problem statement……………………………………………………………………......4
General Problem Statement ………………………………………………………4
Solution Approach …………………………………………………………………4
Operating Environment ………………………..……………………………………..…5
Intended Users …………………………………………………………...………….5
Intended Uses ………………………………………………………………………..5
Assumptions and Limitations …………………………………………………………..5
Assumptions …………………………………………………………………………5
Limitations ……………………………………………………………………………6
Expected End Product and Other Deliverables ……………………………………..6
Proposed approach ……………………………………………………………………..6
Functional Requirements …………………………………………………………6
Constraint Considerations ………………………………………………………..6
Technical Approach …………………………………………………………………..….7
Technical Design ………………………………………………………………..….7
Control Software …………………………………………………………..……….8
Output to laptop ………………………………………………………………..,….8
Microcontroller ………………………………………………………………….….8
Antenna …………………………………………………………………………...….8
Receiver …………………………………………………………………………..….8
A/D …………………………………………………………………………………….9
RMS detector ………………………………………………………………….…….9
Wide band noise generator ……………………………………………………….9
Testing description …………………………………………………………………...….9
Commercialization ……………………………………………………………………….9
Risks and Risk Management ……………………………………………………..…….9
Proposed Milestones………………….…………………………………………..10
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End product description …………………..…………………………………….10
Estimated Resources and Schedules ……….………………………………..10
Personal Effort Budget ………………………………….……………………….10
Financial Budget ………………………………………………………………….11
Schedules ………………………………………………………………………….12
Project Team Information ………………………………………………………..13
Team Members ……………………………………………………………….…….13
Summary …………………………………………………………………………….13
References …………………………………………………………………...…….13
List of Figures:
Figure 1: Visual Project Description ……………………………….……...…… 5
Figure 2: Suggested System Design ………………………………....…….….. 7
Figure 3: Project Schedule …………………………………………..…………...12
List of Tables:
Table 1: Estimated Project Costs …………………………………………...…...11
Table 2: Estimated Personnel Effort in Hours …………………………………11
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Definition of Terms:
A/D: Analog to digital converter
GSM: Global system mobile
ISM: Industrial scientific and medical
PCB: Printed circuit board
PCS: Personal communication service
RF: Radio frequency
U-NII: Unlicensed national information infrastructure
Acknowledgement:
The team would like to thank Jim Mitchell and his employer, Rockwell
Collins, Inc. for supporting this project. Rockwell Collins will provide technical
expertise as well as funding for this project.
We would also like to thank Dr Steve Russell for his invaluable
counseling and precious time.
2) Problem statement
2.1 General Problem Statement:
The design team will complete the current design, construct, test, and
demonstrate a custom, portable, high speed RF power level capturing system for
capturing and displaying local RF power levels in and around an aircraft. The
system must measure the power present in the IEEE 802.11a wireless standard
(5.150-5.350GHz and 5.725-5.825 GHz), IEEE 802.11b wireless standard (2.402.483GHz) and the American PCS cellular phone (1.850-1.990GHz) standard.
The unit must be battery powered, capable of incorporating a variety of antenna
designs, and interface with a laptop computer through a compatible with a RS232C Serial Communication port. RF power levels captured by the system must
be quickly read and stored in a table and graphically displayed on the laptop
computer. The table increment interval triggering will be controlled by another
software application to be supplied by Rockwell at a later date.
2.2 Solution Approach:
The general approach taken to solve the problem was to construct an RF
receiver to operate in the required frequencies. The receiver would have external
connections for antennas and a data link connection to the laptop computer
supplied by the user of the device. The system will be battery-powered, capable
of incorporating any antenna design and compatible with a laptop computer’s
serial port. A microcontroller (current selection is MC68HC11) will be used for
A/D conversions and communications between the RF circuit and the laptop. The
input to the RF circuit will be one or more antennas for receiving the signals in
the desired bands. The interfacing between the microcontroller and the laptop
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would be done using a readily available programming language(C++ is the
current choice).
3 Operating Environment:
The system will need to operate in and around an aircraft that could be
outside on a tarmac or inside a hanger. Hence it should be able to operate at
temperatures ranging from -30C to 45C. This system will be able to operate in
any environment suitable for a laptop computer.
4 Intended Users:
The users will be people who are interested in knowing the RF power
levels in the GSM, 2.4 GHz and 5.0GHz frequency bands around an aircraft.
Possible users could include aircraft maintenance technicians and engineers
performing testing in and around an aircraft.
4.1 Intended Uses:
Intended use of the system is to allow Rockwell Collins the ability to
quickly measure the RF power levels from the specified frequency bands in and
around an aircraft. The system would just measure the RF levels in the desired
bands.
5 Assumptions and Limitations:
5.1 Assumptions
This team will assume that no RF power level detection is required outside
of the frequency bands specified (IEEE 802.11a, IEEE 802.11b, and PCS).
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All needed discrete parts, components and circuit boards will be available
either as samples from vendors or provided by Rockwell or the ECPE
department.
The power supply for the receiver was not taken as an issue and it is
assumed that enough power for the safe functioning of the system should
be provided by an appropriately sized battery.
The battery life would be the same as of the laptop computer.
5.2 Limitations


The speed at which the system takes measurement will be limited by the
speed of the available hardware to detect and transform the signals to a
power level.
System operation will be limited by the work environment suitable for a
laptop computer.
6 Expected End Product and Other Deliverables:
The end product is a portable self powered device for scanning the RF
power levels of specified frequencies band in and around an aircraft. The
sampling of the frequency bands will occur at a user specified rate or
manually. The system will contain the following items:
 System Power will come from an internal battery source
 Multiple band receiver(s) and antenna(s) for specified frequency bands
 RF power level detection circuitry to provide sample measurements.
 Data Communications between receiver and laptop with control software.
 Laptop Software for display and control measurement result.
7 Proposed approach:
7.1 Functional Requirements:
The system should be able to capture RF power levels in the following
frequency bands.
 PCS:
1.850-1.990 GHz
 IEEE 802.11b 2.40-2.483GHz
 IEEE 802.11a 5.150-5.350GHz and 5.725-5.825 GHz
RF power levels captured by the system should be quickly read, displayed on
the laptop and stored in a table
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a timestamp for future use. The graphical display of RF power levels should
be in real time.
7.2 Constraint Considerations:
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Compatibility: Control software should be windows compatible.
Interface: The data interface needs to be compatible with a computer
serial port.
Portability: System needs to be easily transported and operated by hand.
Programming: Control software should be written in a common higher
level language( such as C or C++)
Power: Needs to have a self-contained power source.
8 Technical Approach:
RF signals would be captured by a receiver tuned to the appropriate
frequency bands, interpreted by a microcontroller, and the data sent to a laptop
computer where the power level would be displayed on a graph. The graph of
each frequency band would be updated at either user selected rate or manually.
The system would be tethered to a laptop computer at all times by the data link.
The client has requested the 5.0 GHz U-NII frequency range be
incorporated first to allow for the detection of IEEE 802.11a Wireless LAN
products.
8.1 Technical Design:
The team’s approach to this design to use available off the shelf
components to satisfy the design requirements for the project. The design will
center on a low cost, low power microcontroller to manage the control of the
receiver(s) and serial computer interface to the laptop.
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8.2 Control Software:
The software desired would be running in a Windows environment on a
laptop computer. Its purpose will be to control the sampling and display a graph
showing the strength of the RF power levels in the specified bands. The software
will update the graph of each band at a user selected rate or manually. The
incoming data will also be stored in a timestamp table for later use or review.
8.3 Output to laptop:
The computer interface to the laptop computer will be an industry
standard protocol to allow portability of the device to other computers. The
methods of communicating the data considered were:
 RS 232-c
 USB
 Parallel port
RS 232 was selected as the interface based on the selection of the
microcontroller which has built in serial capabilities.
8.4 Microcontroller:
An ultra low power digital microcontroller will be needed for data and
control processing. The Motorola MC68HC11F1 was chosen as the initial
microcontroller since it incorporates a built in 8-bit A/D converter, has built in
serial port communications, low cost, the availability of prototyping boards and
software on campus and all the members of the design team have had
experience with this development board in their undergraduate studies. The main
purpose of the microcontroller is to convert the incoming analog signal to digital
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bits and output the digital bit stream to a laptop via the built in serial interface as
well as provide some switching on the input multiplexer for input channel
selection.
8.5 Antenna:
An antenna will be selected to provide optimum reception in each of the
desired frequency ranges. Designs to be considered are:
 Disc-cone
 Log-Periodic
 Dipole
A commercial log periodic antenna will be purchased to provide the team with a
known base line when taking test measurements of signal strength and gain. The
client has also expressed interest in the ability to use dipole antennas with this
instrument. To accommodate these alternatives, an external connection will be
provided to enable any antenna to be attached to the system.
8.6 Receiver:
Originally, commercially available transceivers were considered for the
design. Since these parts are highly specialized by application such as cell
phone, wireless LAN cards or cordless phones, a more general approach has
been taken. A series of filters and down converters will be used instead of
commercial transceivers. This allows flexibility in the types of the signals to be
observed in the specified bands. By adjusting the local oscillator frequency, many
frequency ranges within a band maybe observed. It is possible that several of the
components maybe incorporated into one chip depending on the availability of
suitable RF parts.
8.7 A/D:
A/D converters are needed for converting the analog voltage representing
RF signal level into a digital representation of signal level. The selected
microcontroller has a built in 8-bit A/D converter.
8.8 RMS detector:
The RMS detector converts the receive RF signal into a linear DC
voltage. This linear voltage is a measurement of the RF signal strength and after
being converted to digital information by the A/D will output to the laptop
computer for display.
8.9 Wide band noise generator:
A Wideband noise generator is used as a calibration source to provide a
baseline threshold signal level. This will be the reference power level to
determine if a signal is present as compared to random noise.
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9 Testing description:
This system will be tested in multiple phases with each functional block of
the design tested individually to ensure proper operation. The frequency ranges
will be implemented individually to allow testing on the devices being
implemented without disturbing previously implemented hardware. Control
software for the microcontroller will be tested on the development board to
ensure bug free operation. The user software running on the laptop computer will
be tested for proper operation with the microcontroller prior to connection to the
receiver unit. Once all functions are operational, a PCB will be manufactured and
the compete system tested. The team will conduct testing and if advance testing
facilities or resources are required, the client will try to make these available to
the team.
10 Commercialization:
The opportunity for commercialization of this product is low because it is
specialized to the needs of the client. The targeted user would have to have very
similar needs which are primarily a need for a portable meter with the capability
to store the signal information. This requirement is beyond most handheld field
meters. If the measurement accuracy can be proven, this device would be used
in a laboratory or in a school lab environment where budget is a consideration.
11 Risk and Risk Management:
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Below is a list of risks possibly effecting the completion of the project:
Team Member Loss: Talent and knowledge are evenly distributed within
the group: consequently the loss of any member will result in a
redistribution of hours and duties to ensure project completion.
Part unavailability: Unavailability of chosen parts can greatly affect
progress, so it may be necessary to substitute similar parts. The client will
make the best effort to provide all necessary parts for the project.
Design Problems: Technical problems with implementing the functions
could arise. In this instance, additional help maybe sought and alternative
solutions created. The client has agreed to provide technical assistance as
needed.
12 Proposed Milestones:
The design team has identified the following project milestones. The
success of the project can be determined by the completion of all the milestones
listed:
 Project Definition: Completion of the Phase-II project description and
requirements.
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Project Design: Completion of a detailed hardware and software design,
including schematics, parts list, software module descriptions, and
software programs.
Functional Prototype: Complete prototype constructed for thorough
testing
Prototype testing: Complete thoroughly testing of each prototype system
Prototype revisions: Complete prototype revision based on updates
from testing.
Documentation: Thoroughly document the entire system from the initial
design to the final system design.
Demo Project to Client: The final system will be demonstrated to the
client as well as the industrial review board.
13 End product description:
The end product is a portable self-powered device for scanning the RF
power levels of specified frequency bands in and around an aircraft. The
sampling of the frequency bands will occur at a user specified rate or
manually. The system should contain the following items:
 System power will come from an internal source
 Multiple band receiver(s) and antenna for specified frequency bands
 RF power level detection circuitry to provide sample measurements
 Data communication between receiver and laptop with control software
14 Estimated Resources and Schedules:
14.1 Personal Effort Budget:
Below is the estimated number of hours that each team member will
spend in each of the projects modules. These are projected estimates and the
final hours should resemble the hours listed below:
Estimated Personal Time In Hours
Team
member/Task
Tausif Basit
Ahmed
Fazal
Class
Deliverables
Research
Hardware
Design
36
28
24
27
Total
Task
115
30
44
24
40
27
15
28
42
109
141
Per
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Software
Design
Prototyping
Revisions
Documentation
Total
per
person
15
12
45
37
109
53
27
20
225
56
28
22
210
48
23
23
205
52
31
25
242
209
109
90
Total
Hours
Team
882
14.2 Financial Budget:
The financial budget shows the expected cost for all projected project
items. Rockwell Collins will attempt to provide funding for all parts. The team will
also rely on samples for the initial design and prototype phase. These figures
estimate and reflect the availability of parts from Rockwell Collins, Inc... Currently
the only costs incurred by the project members are printing of the posters and
miscellaneous documents.
Item name
Poster Printing
Poster Lamination
Poster Mounting
Miscellaneous Printing
Components
Laptop Computer
Assembly
Total
Projected Cost
$ 55.00
$ 25.00
$ 10.00
$ 20.00
$ 1,000.00
$ 1,500.00
$ 250.00
$ 2860.00
15)Schedules
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Project Team Information:
Client:
Faculty Advisor:
Jim Mitchell
Steve Russell, Ph.D.
Rockwell Collins, Inc.
MS 108-205
400 Collins Road, NE
Cedar Rapids, IA 52498
Ph: 319-295-2031
Fax: 319-295-8823
Email: [email protected]
2427 Coover Hall
Iowa State University
Ames, IA 50014
Ph: 515-294-1273
Fax: 515-294-8432
Email: [email protected]
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Team Members:
Tausif Ahmed Awan
Team Leader
121 B University Village
Ames, IA 50010
Phone: 515 572 4873
E-Mail: [email protected]
Fazal Haq
112 F University Village
Ames, IA 50010
Phone: 515 572 4887
E-Mail: [email protected]
Abdul Basit Malik
Communications Coordinator
112 F University Village
Ames, IA 50010
Phone: 515 572 4887
E-Mail: [email protected]
Ahmed Mir
112 F University Village
Ames, IA 50010
Phone: 515 572 4887
E-Mail: [email protected]
16 Summary:
RF spectrum analyzers that are currently available are either too slow or too
expensive for this application. By designing and building a customized RF power
level capturing system for specified frequencies, the system will be low cost, low
power, and have high speed sampling capabilities. The real-time data display
provides for timely results and data storage allows for future use and reference.
17 References:
There are no references available at this time.
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