A distributed amplifier with 12.5dB gain and 82.5-GHz bandwidth using 0.1 mu m GaAs metamorphic HEMTs

Abstract

In this letter, the monolithic distributed amplifier with active control scheme is presented, using 0.1 mu m GaAs metamorphic HEMT technology, with a maximum operating frequency of 315 GHz. Active feedback resistor, which adjusts the negative resistance generated by the cascode gain cell, is employed to maximize the bandwidth of the entire distributed amplifier without oscillation. The measurement of the distributed amplifier with 5 cascade gain cells shows the gain of 12.5 +/- 1.2 dB and 3-dB bandwidth of 82.5 GHz correspondhig to the ultrahigh gain-bandwidth product of 347 GHz. Group delay variation is also measured to be less than +/- 8.9 ps up to 60 GHz. (c) 2007 Wiley Periodicals, Inc.