驱动器/放大器

What Is a Driver/Amplifier Module?

OVERVIEW

Driver/amplifier modules amplify high-speed modulation signals to drive optical modulators used in optical communications.
There are two categories of drivers/amplifiers: linear amplifiers, and limiting amplifiers.
Linear amplifiers amplify the input signal at a fixed ratio and the output level is proportional to the input level. Conversely, with a limiting amplifier, when the input level exceeds a certain level, the output level is limited to a fixed level and amplified.

Linear amplifiers faithfully amplify the input signal. Linearity is a fidelity index of amplification. In recent years, multi-level signals such as PAM4 (Pulse Amplitude Modulation 4) have been used in optical communications. Using poor-linearity amplifiers for these multi-level signals results in distorted output waveforms, and use of good-linearity amplifiers is necessary for faithful amplification of PAM4 signals. The input/output operation image of a linear amplifier is shown in the figure below.

Limiting amplifiers limit the output to a fixed level and are used when the input level to the latter stage is restricted by a binary signal such as NRZ, or in situations requiring digital processing in the latter stage. A limiting amplifier may also be used for waveform shaping to compress waveform distortions, such as ringing or overshooting of the input signal. The input/output operation of the limiting amplifier is shown in the figure below.

Driver/Amplifier Lineup
Anritsu’s driver/amplifiers are manufactured using our proprietary InP-based HBT process and feature high speed and high reliability. The product line includes a differential linear amplifier for 56 Gbaud PAM4 signals, which is the mainstream in 400GbE, and a single linear amplifier for 140 Gbaud PAM4 signals, which is being considered for the next-generation 800GbE/1.6TbE communication standard.