1394b Design for Gigabit Optoelectronic Data Communication

1
1394b Design for Gigabit Optoelectronic Data
Communication

• Group G9
• Tiffany Lovett, gte291r
• Mareisha Winters, gte824t
• Presented By
• Tornya Moore, gte668r
• ECE 4006 C
• Spring 2002

2
Objective

• Design Considerations for VSCEL
• Link Budget Analysis
• Design of the VSCEL board
• Testing
• Future Testing

3
Design Considerations for the VCSEL

• Two candidates
• Honeywell HFE4380-521
• Honeywell HFE4384-522
• Threshold current-minimum amount of current
  needed for the VCSEL to emit light
• Slope Efficiency-tells how many amps it takes to
  produce a given power output

4
Comparison of Two VCSEL Candidates
HFE4380-521
HFE4384-522
5
Link Budget Analysis

• Link budget analysis is the calculation and
  verification of the operating characteristics of
  a fiber optic system
• Prior to implementing or designing a fiber optic
  circuit, a budget analysis is recommended to make
  certain the system will work over the proposed
  link
• For this project the purpose of the link budget
  is to determine whether the transmitter and
  receiver system provide sufficient current to
  drive the post amp.

6
Link Budget Analysis (Contd)


7
Design of the VCSEL Board

• In order to minimize reflections the VCSEL
  circuit had to have a total resistance of 50?
• A surface mount resistor of 25? was placed in
  series with the VCSEL. Which has a typical
  resistance of 25?
• A DC bias T (2k? resistor in series with the 5V
  power supply) was connected to the circuit to
  allow connect to the AC coupled GTS 1250 pattern
  generator

8
Design of the VCSEL Board (contd)

• Once all of the components were gathered they
  were mounted on the board and soldered onto the
  board.

9
Testing

• The two pieces of equipment that will be used to
  verify the functionality of the components are
  the Tektronix GTS 1250 pattern generator and
  Tektronix 7000 Series Oscilloscope.

10
Testing (contd)

• Initially tested the Agilent opto-electronic
  board from the previous semester to generate an
  eye diagram
• GTS 1250 was connected to the transmitter portion
  of the board,the oscilloscope was connected to
  the receiver portion, and a fiber cable was used
  to loop the receiver and transmitter together
• Tested the VCSEL board by connecting it to the
  GTS 1250 and then to the Agilent board
• Tried to test the VCSEL board with the MAXIM
  transmitter board but no diagram appeared

11
Testing (contd)

• Block diagram of test setup for VCSEL

12
Testing (contd)

• Eye diagram of Agilent board

13
Testing (contd)

• Eye diagram of VSCEL board

14
Future Testing

• To test the VCSEL board with the MAXIM
  transmitter board
• To implement the design for the photodetector
  circuit
• To design VCSEL and photodetector boads using
  SuperPCB layout package.