Ku-band Low Phase Noise Frequency Division Phase-locked Oscillator Source Research

Frequency source is the heart of microwave electronic systems which directly affects the performance of the entire system. With the development of microwave technology, the system’requirements of various performance of frequency source are also increasing. With its good phase noise performance, small size and other characteristics, Dielectric resonator is becoming a good choice of microwave frequency sources. For the needs of engineering practice, a Ku-band dielectric resonator is designed.First, the theory of the dielectric oscillators is expounded, coupling model of dielectric and microstrip in dielectric resonator is studied, and several dielectric oscillator circuits are analyzed. The relationship of coupling coefficient and loaded quality factor of resonator is analyzed in detail combined with theory. Use simulation software such as HFSS and ADS to design series reflective and parallel feedback DRO with the same components. The design works include the HFSS simulation of DR, negative resistance circuit design, fan-shaped line design and directional coupler design. With comparing the performance of these two forms of DRO and the actual needs, the series reflective DRO is selected as the oscillator. Methods which can improve phase noise is proposed combined with the actual.Second, in order to get a better phase noise and stability, PLL frequency source is designed by frequency division first and then phase locked. The PCB layout of PDRO is showed and processed. The Cavity of PDRO is also designed and processed.Finally, the debugging process of PDRO is finished and the phase noise achieves-87dBc@1KHz,-96.3dBc@10KHz,-93dBc@100KHz and the harmonic suppression is greater than35dB. The measured results basically meet the design specifications.