Comparison of LNA and TIA as optoelectronic receiver front-end strategies for phase noise reduction in low-power miniaturized OEOs.

In satellite communications, aerospace navigation, and 6G mobile networks, there is an increasing demand for miniaturized optoelectronic oscillators (OEOs) to enable lightweight, reliable, and compact deployment. However, integrated OEOs reduce output optical power. This reduction in optical power significantly increases the relative noise contribution from optoelectronic (OE) receiver front-end (FE) amplifiers and degrades system noise performance. This paper studies the role of OE receiver front-end amplifiers-a commercial low noise amplifier (LNA) and a custom transimpedance amplifier (TIA)-for integrated OEOs, by evaluating their performance in a single-loop OEO that generates 20 GHz signals. Compared to the LNA, the TIA reduces phase noise by approximately 7-9 dBc/Hz at 10 kHz and the noise floor by 10-12 dBc/Hz at 100 kHz; under low optical power conditions, it achieves -121.5 dBc/Hz at 10 kHz and -142.1 dBc/Hz noise floor. This TIA scheme is more effective against the noise problem caused by reduced optical power in integrated OEOs and supports high-performance signal output in demanding application scenarios.