The Study For Low Phase Noise Of Microwave Frequency Source Based On The Optoelectronic Oscillator Technology

The microwave source, which has low phase noise and high frequency stability has a significant impact on the performance of radar, communications and other microwave system, and greatly limits the performance improvement of the microwave system. With the continuous development of technology, various microwave systems improving up the various performance requirements of the microwave source day by day, the traditional source of microwave technology no longer meet their requirements. In this paper, microwave frequency source, based on OEO technology, high frequency output, low phase noise, meet the various requirements of microwave systems and the increasing performance.In this paper, microwave frequency source, based on OEO technology and had low phase noise, is set up by opto-electric hybrid resonator to generated microwave signal. This paper analyzes the basic structure and the basic principles of the OEO’s start-up conditions, the phase noise characteristics of the OEO, the fiber optic transmission and the corresponding solution for the stability of the output signal and side-mode suppression in terms of theoretically. In this paper, the phase-locked loop technology used to improve the stability of OEO’s output frequency. multi-ring optical fiber transmission used to OEO side mode suppression.Some key of OEO microwave devices made a detailed presentation in this paper, which includes a low noise amplifier, a microwave narrowband filter and a phase locked loop module. For LNA, this paper elaborates the role of the LNA in the OEO, and then determine the parameters of LNA required in accordance with OEO. After introducting of the LNA design theory, this paper use ADS simulation software to design the LNA circuit, simulation and optimization. For narrow-band microwave filter, firstly, this paper describes its key role in the OEO, and determines the parameters according to the OEO system. This paper introduce two methods to design microwave narrow-band filter, which are the coupled microstrip lines and SIW. After comparison, coupled microstrip lines narrowband filter microwave performance indicators deviation, so in this paper without making too much description, but the physical test data of SIW microwave narrowband filter meet the OEO system requirements. For phase locked loop module, the design use a PLL semiconductor chip design, and produce a phase locked loop module to do the test experiments.By selecting the experimental test programs and building OEO system, repeated experiments show the feasibility and advantages of OEO. Experimental results show that the design of OEO with high spectral purity of the output 10 GHz microwave signal, the phase noise of up 126 dBc / Hz @100KHz, side mode suppression of up to 35 dB.Based on low-noise microwave oscillator frequency source photoelectric technology, which can output high-frequency, high stability and low phase noise frequency source. According to the study of heat and domestic and foreign experts present, their research results we can see that there is very broad prospects.