Ultralow-phase-noise millimetre-wave signal generator assisted with an electro-optics-modulator-based optical frequency comb

• Published in: Scientific reports 2016-05, Vol.6 (1), p.24621-24621, Article 24621
• Main Authors: Ishizawa, A., Nishikawa, T., Goto, T., Hitachi, K., Sogawa, T., Gotoh, H.
• Format: Article
• Language: English
• Subjects: 639/624/1111/1112; 639/624/1111/1119; Equipment Design; Humanities and Social Sciences; Microwave communications; multidisciplinary; Noise; Optics; Optics and Photonics - instrumentation; Science; Signal Processing, Computer-Assisted; Signal-To-Noise Ratio
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep24621

Low-noise millimetre-wave signals are valuable for digital sampling systems, arbitrary waveform generation for ultra-wideband communications and coherent radar systems. However, the phase noise of widely used conventional signal generators (SGs) will increase as the millimetre-wave frequency increases. Our goal has been to improve commercially available SGs so that they provide a low-phase-noise millimetre-wave signal with assistance from an electro-optics-modulator-based optical frequency comb (EOM-OFC). Here, we show that the phase noise can be greatly reduced by bridging the vast frequency difference between the gigahertz and terahertz ranges with an EOM-OFC. The EOM-OFC serves as a liaison that magnifies the phase noise of the SG. With the EOM-OFC used as a phase noise “booster” for a millimetre-wave signal, the phase noise of widely used SGs can be reduced at an arbitrary frequency f (6 ≦  f  ≦ 72 GHz).