| Photonic microwave generation technology can realize the generation of high frequency microwave signals with low phase noise,possessing important application prospects and research value in the fields of wireless communication,radar,electronic warfare and basic scientific research.At present,photonic microwave generation technology faces the challenge of achieving low phase noise performance and miniaturization simultaneously.Therefore,this thesis will focus on the miniaturization requirements of high-frequency and low-phase-noise microwave signal sources,and conducts research from three aspects:the realization of ultra-low phase noise of photo-generated microwave systems,the compact design of turnkey type and high-quality integration.The main innovative achievements are as follows:The thesis studies the generation technology of ultra-low phase noise microwave signal of optoelectronic oscillator.Firstly,the dominant noise suppression technology of optoelectronic oscillator system based on voltage-controlled delay frequency modulation is proposed,which realizes the generation of X-band microwave signals with extremely low phase noise(-151dBc/Hz@10kHz).In addition,a self-regenerating frequency division optoelectronic oscillation technology with equivalent large-scale phase shifting and high-Q filtering in the millimeter-wave band is proposed,which produces a 40GHz millimeter wave(MMW)signal with the singlesideband phase noise of-117dBc/Hz@10kHz,a spurious suppression ratio greater than 80dBc,and high frequency stability.degree(2.96×10-13,7 orders of magnitude higher than the free running MMW OEO),realizing the overall performance optimization of the millimeter-wave band lowphase-noise optoelectronic oscillation frequency source.The thesis studies the compact turnkey microwave signal generation technology of optoelectronic oscillator.Firstly,an anti-polarization disturbance technology based on a Sigma fiber ring cavity is proposed,realizing an X-band coupled optoelectronic oscillator(COEO)which is immune to polarization disturbance.In addition,a supermode suppression technology based on the semiconductor optical amplifier(SOA)with fast gain saturation effect for coupled optoelectronic oscillator is proposed,and the X-band turnkey COEO with phase noise up to-133dBc/Hz@10kHz and spurious suppression ratio greater than 90dBc is realized through making the SOA work at a transparent state.The compact turnkey photonic microwave signal source provides a reliable technical route for photoelectric oscillators for engineering practice.The thesis studies the high-quality integration technology of a new type of photonic microwave signal source.For the first time in China,a highly coherent and stable Kerr soliton optical frequency comb was generated in a high-Q(>109)magnesium fluoride crystal microcavity,and the optical frequency division technology was used to generate a Ku-band(17.09GHz)microwave signal.The "quiet point" tuning method further realizes the phase noise performance optimization(-120dBc@10kHz,free running state),which provides important technical support for the realization of low phase noise miniature photonic microwave signal sources. |
