Abstract

Schemes using an interstage optical isolator or narrow bandpass filter in single pumped two-stage amplifiers have been shown to achieve both high gain and low noise performance.^1–3 These schemes also provide the constant output signal power (±1 dBm) over a limited range of input signal powers, called the dynamic range. However, these schemes inherently have a trade-off between dynamic range and noise figure (NF).⁴ In this paper, we compare the proposed three-stage amplifier⁵ with the existing two-stage amplifier at a viewpoint of dynamic range, gain and noise figure.

© 1995 IEEE