A DC to 40 GHz, high linearity monolithic GaAs distributed amplifier with low DC power consumption as a high bit-rate pre-driver

Abstract

This paper presents the design and the performance of a six stage GaAs MMIC distributed amplifier (DA) for optical driver applications. The DA is fabricated in a commercially available 0.15 μm GaAs p-HEMT technology. The amplifier exhibits 13 dB of small gain over 40 GHz of 3 dB bandwidth with a power consumption equal to 550 mW. Group delay time variation up to 30 GHz is only ±7 ps. The output power is higher than 16 dBm (4 V pp ), which makes the circuit suitable as a preamplifier for lithium-niobate (LiNb03) optical modulator driver. The DA is demonstrated as a part of the modulator driver in a 12.5 GBps PAM-4 (25Gbps) optical system by using the eye diagram as a figure of merit.