Font Size: a A A

Key Microwave Photonics Techniques In Low Phase Noise Microwave Generator And Broadband THz Communications

Posted on:2018-09-18Degree:DoctorType:Dissertation
Country:ChinaCandidate:S JiaFull Text:PDF
GTID:1318330542981201Subject:Communication and Information System
Abstract/Summary:PDF Full Text Request
Microwave photonics is an emerging technology intermingling microwave technologies with the photonics.It utilizes the low loss and ultra-broadband characteristics of the optical fiber technologies to complement the traditional microwave technologies.Two important research areas based on microwave photonics are covered in this thesis,namely photonics-enabled microwave signal generation technologies,with a typical example of optoelectronic oscillator(OEO),and ultrahigh-speed THz photonic wireless communications.An ultra-long optoelectronic cavity resonator is constructed in an OEO utilizing the low loss characteristic of the optical fiber.Such a structure capable of generating microwave signal with ultra-low phase noise far superior to the conventional microwave generator,has attracted great attention.For the first time,a novel scheme of dual-loop OEO with two wavelengths based on wavelength multiplexing is proposed and included in this thesis.In addition,we also for the first time adjust the OEO by three levels by employing a YIG microwave filter,a tunable optical delay line and a phase-locked loop module.Finally,an engineering prototype of OEO has been successfully developed.We realize 6-Hz step frequency tunability of its output signal within 8-12 GHz range.The phase noise,linewidth and side mode suppression ratio of the generated 10-GHz signal are-141.28 dBc/Hz@10 kHz,5.2 mHz and 70 dB respectively.The frequency drift of the oscillator frequency is less than ±1 Hz within 24 hours.The engineering prototype of OEO has been exhibited,measured and widely recognized by relevant organizations.In terms of the applications of the OEO,a novel approach of generating short optical pulses based on a dual-loop OEO with two wavelengths is demonstrated.The dual wavelengths of the short optical pulses with low timing jitter are generated simultaneously.The THz wireless communications target to support emerging ultra-broadband services,and the THz photonic wireless communication technologies in the frequency range above 300 GHz have significant research value.In this thesis,a novel approach of generating THz carriers with a uni-travelling carrier photodiode(UTC-PD),a broadband THz receiver and an optical frequency comb is proposed and experimentally demonstrated.By investigating the coherent compensation technique in the system,single-channel THz wireless transmission and fast demodulation of various modulation formats,including OOK,QPSK,16-QAM and 32-QAM,are demonstrated.By utilizing the techniques of signal distortion compensation,single-channel THz wireless transmission and demodulation of 16-QAM signal are demonstrated with the capacity of 128 Gbit/s.In terms of the multi-channel transmissions,by using the coherent compensation technique,THz wireless transmission and fast demodulation of 8-channel QPSK signal in the 300-500 GHz band are demonstrated with the capacity of 160 Gbit/s,and 4-channel 16-QAM signal THz wireless transmission and fast demodulation in the 375-450 GHz band,with capacity of 80 Gbit/s are demonstrated.Finally,by utilizing the techniques of signal distortion compensation,a 6-channel 16-QAM signal THz wireless transmission in the 300-500 GHz band,with the throughput of up to 300 Gbit/s is also demonstrated.To the best of our knowledge,this is the highest published bitrate record of THz wireless transmission in the THz band above 300 GHz.
Keywords/Search Tags:Optoelectronic oscillator(OEO), Ultra-low phase noise, Frequency tunability, THz wireless communication, Ultrahigh speed, Uni-travelling carrier photodiode(UTC-PD)
PDF Full Text Request
Related items