FM CONVERTER

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FM CONVERTER
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Team Members
Dan Harkins Team Leader
George Henry
Dr. Georgios Lazarou Advisor
Beau Blackwell
Shawn Welch
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Team Responsibilities
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Project Significance

• Car radios do not have audio inputs

• Many cars only have a CD or cassette player

• FM converter can be used with FM radio

• Keeps the owner from having to buy and install
  entire audio system

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Current Technology Options

• Cassette adapters are the most widely used means
  to play one audio device through another

• Cassette Player Adapters

Existing tape player needed
Excess wiring can get in the way
Limited signal quality
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Design Diagram
Signal from Audio Device
Process Signal (Convert to FM Signal)
Transmit Converted FM signal to FM receiver
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Implementation
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Design Specifications
1. Operating Frequency Operate throughout on
the standard FM radio range (87.9-107.9 MHz)
2. Weight Target weight is eight ounces
3. FCC Requirements Must be compliant with
Part 15 of FCC regulations
4. Signal Clarity The unit will be able to
broadcast a stereo signal through the air
5. Packaging Final product will be
approximately 5 x 3 x 3

• 6. User Interface The unit will feature
• push-button style tuner
• LCD to display the operating frequency
• Input signal LED

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Design Specifications
7. Durability Must be resilient to the bumps
and bruises that can occur to a portable
device.

• 8. Power Requirements Will operate off
• Four AA batteries
• AC converter
• 12V DC Adapter

• 9. Cost
• Prototype Components 80 90
• Mass production costs approximately
• 10- 20 of our prototype cost

10. Audio Input The converter will use RCA
audio inputs.
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Benefits of RCA Connection

• Cord more commonly used and widely available
• Greater versatility
• RCA inputs offer the possibility to use both RCA
  and headphone outputs
• Increased cord life
• Cords can be removable for storage
• User can replace worn or damaged cord without
  having to replace the entire unit

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Benefits Over Tape Adapters

• Portability

• No wires to connect to FM receiver
• Light-weight
• Can be used with any FM receiver

• Signal Clarity

• No tape hiss

• Low interference

• Automotive design minimizes interference

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Benefits of FM vs. AM

• More widely used than AM radio
• Consumers more familiar with FM dial
• Better signal to noise ratio
• Less interference than AM radio
• Nearby electronic devices can cause noise
• Even weather can cause static on AM radio

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Typical Decibel S/N Ratios
AM broadcast / telephone 25 dB (worst)
Audio Cassette Player 35-45 dB
FM broadcast 50-60 dB
Compact Disc 90-105 dB (best)
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Test Specifications
Design Constraints
Radio Frequency
Signal Strength
Operation Voltage
Antenna Efficiency
Signal to Noise Ratio
Reliability
Pspice






Matlab






Performance Test






O-Scope






Spectrum Analyzer






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Simulation
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Jan Feb Mar Apr May
Aug Sep Oct Nov Dec
Research
Prototype
Simulation
Performance Testing
Debugging
Final Documentation
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FM CONVERTER