Impedance-matched optical link for C-band satellite applications

Optical transmitter and receiver modules with passive impedance-matching circuits have been designed, constructed, and tested. A direct current modulated InGaAs DFB laser, operating at 1.3 micron, and an InGaAs PIN photodiode were matched to 50 ohms with passive, mixed lumped and distributed element, matching circuits. A link-insertion loss of 21 dB with a 3 dB bandwidth of 900 MHz has been demonstrated. Through the use of higher-order matching circuits, link-insertion loss variations across the satellite downlink frequency band (3.6-4.2 GHz) have been kept below /spl plusmn/0.5 dB.<
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