Research On Key Technologies Of Miniaturized Photoelectric Oscillators

As the core of microwave communication system,signal source directly affect the performance of the entire system.The traditional microwave signal sources have certain limitations in terms of phase noise and other indicators,while the optoelectronic oscillator(Optoelectronic Oscillator,OEO),as a new type of microwave signal source,is capable of generating microwave signals with extremely low phase noise and has great potential in the fields of electronic countermeasures,radar,and communications.However,most of the current OEO are built using discrete microwave and optical devices and have become larger due to the device and connecting cables,which is not conducive to integration into microwave systems.To solve this problem,this thesis miniaturizes the OEO by miniaturizing the microwave circuit.The main research of this thesis is as follows:1.In this thesis,a partially integrated miniaturized OEO is designed and implemented.Firstly,the system structure scheme and chip model are determined according to the index requirements;then the simulation software is used to simulate and analyze the microwave circuit of OEO;finally,the partial integration of the OEO microwave circuit and the detector is achieved.After processing and testing,the output frequency of this part of the integrated miniaturized OEO is 10 GHz,the output power is 6.92 dBm,and the phase noise is-119.66 dBc/Hz at 10 k Hz off the center frequency.2.A miniaturized OEO microwave circuit based on multilayer PCB(printed circuit board)structure is designed in this thesis.Embedding the power divider and combiner in the OEO microwave circuit inside the substrate,this scheme utilizes a vertical via transition structure to achieve signal transmission between the upper and lower substrates.Compared with the cascaded structure,the circuit size is reduced by71%,and the circuit loss is increased by less than 0.5dB.3.In this thesis,a filter power divider based on dielectric resonator is designed.And the miniaturization of the microwave circuit of the photoelectric oscillator is achieved by using this structure.Filter power division fusion structure is realized by using Dielectric resonator instead of Wilkinson power division quarter transmission line,and then combine the multilayer PCB structure to realize the miniaturization of OEO microwave circuit.Compared with the cascaded structure,the circuit size is reduced by50%,and the circuit loss is by 1.5dB.4.A narrowband filter based on multi-stage dielectric resonator is designed in this thesis.The center frequency of this filter is 10 GHz,with a passband bandwidth of 130 MHz.The insertion loss within the passband is less than 0.5dB,and the return loss within the passband is greater than 17 dB.There are two transmission zeros at 300 MHz on the left and 60 MHz on the right of the passband,and the out-of-band rejection is greater than 20 dB in the frequency range of 2GHz-9.8GHz and 10.1GHz-12 GHz.