Major Progress in Broadband Low-Noise Microwave Synthesis Research at Peking University

The research group led by Professor Zhao Jianye at the School of Electronics Engineering and Computer Science, Peking University, has recently made significant progress in broadband low-noise microwave synthesis. Based on this research achievement, a paper authored by Dr. Hou Dong and others was published in full in December 2013 in Scientific Reports, a journal of the Nature Publishing Group. Building on extensive prior work, the Zhao Jianye group pioneered exploration in broadband, low-phase-noise microwave synthesis, developing a broadband frequency synthesis method by synchronizing a broadband optoelectronic oscillator to a highly stable optical frequency comb. The optical comb naturally possesses high-order harmonics, from which low-phase-noise broadband microwave signals can be synthesized; however, as frequency increases, the power and phase noise performance of its high-order harmonics deteriorate. In contrast, the optoelectronic oscillator exhibits ultra-low high-frequency phase noise at extremely high carrier frequencies. By synchronizing the broadband optoelectronic oscillator to the optical comb, they overcame the frequency limitation in comb harmonic extraction and achieved, for the first time, broadband ultra-low-noise microwave synthesis based on optical comb frequency extraction technology.

Ultra-low-noise microwave synthesis technology holds significant importance for fields such as communications, measurement, and aerospace. In recent years, the research group has achieved a series of outstanding results in optical comb frequency stabilization and low-noise microwave synthesis, published successively in renowned journals including the IEEE Journal of Quantum Electronics, Physical Review Letters, and Optics Letters.

This research was completed in collaboration with the team of Professor Chen Zhangyuan at the State Key Laboratory of Advanced Optical Communication Systems and Networks, with support from the National Natural Science Foundation of China and the National Key Basic Research Development Program ("973 Program").

Source: People's Posts and Telecommunications News