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1394b Design for Gigabit Optoelectronic Data Communication. Group G9: Tiffany Lovett, gte291r Tornya Moore, gte668r Presented By : Mareisha Winters, gte824t ECE 4006 C Spring 2002. Objective . Design Considerations for OE components Link Budget Analysis Testing Procedures.
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1394b Design for Gigabit Optoelectronic Data Communication Group G9: Tiffany Lovett, gte291r Tornya Moore, gte668r Presented By: Mareisha Winters, gte824t ECE 4006 C Spring 2002
Objective • Design Considerations for OE components • Link Budget Analysis • Testing Procedures
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 • Rise/Fall Times
Comparison of Two VCSEL Candidates HFE4380-521 HFE4384-522
Design Considerations for the Photodetector • Two candidates: • Lasermate RSC-M85A306 • Hamamatsu S5973 • Responsivity-measures how much light input is required to produce a given current • Capacitance of the photodiode must not exceed the maximum input capacitance of the MAXIM board. • Rise/Fall Time
Comparison of Two Photodiode Candidates Lasermate RSC-M85A306 Hamamatsu S5973
Link Budget Analysis • Will the system work for 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. • Link Budget = Power Incident on Photodetector x Responsivity of the Photodetector • Power Incident on Photodetector = [Modulation Current of Transmitter x Slope Efficiency of VCSEL] – Losses Due to Connectors and Fiber
Testing • The PIN photodiode and VCSEL will be connected to their own separate boards and connected via optical fiber. These boards will then be connected to the MAXIM Evaluation Kits. • The two pieces of equipment that will be used to verify the functionality of the components are the Tektronix GTS 1250 Bit Error Rate Test Set (BERTS) and Tektronix 7000 Series Oscilloscope.
Testing (cont’d) • The BERTS measures the bit error rate (BER) for a given transmission. • The BER is the percentage of bits that have errors relative to the number of bits received. • BER ~ 10-12 • The oscilloscope displays the data stream as information is transmitted. The data transmission creates an eye pattern. • The preferred sampling time is when the eye is opened the widest.