Ultra-wideband microwave amplifiers for digital optical communications

In this paper, the requirements and the design methods of ultra-wideband amplifiers in digital data transmission at gigabit rates using optical links, which are required to externally modulate the laser diode light on the transmit side, and to amplify the detector diode signal of the receiver, are described. A novel amplifier design technique is proposed and compared with the traditional distributed amplifier equivalent using MESFETs, and produces about 10 dB more gain at the expense of only 3 dB lower output power. Typical measured results are presented showing good 'eye-diagram' performance for both 2.5 Gb/s and 10 Gb/s optical communication external modulator applications.