Low Phase Noise Dro

Oscillators, which usually consisted of active amplifiers and passive frequency selective resonator network, represented the basic microwave energy source in all microwave systems. With the rapid development of microwave-circuit technology, the performance of oscillator, such as phase noise characteristics and temperature stability, was required higher. Therefore, the design principle and engineering practice of low noise dielectric resonator oscillator (DRO) were discussed in this dissertation.The phase-noise characteristic of dielectric oscillator was extremely high. Yet the design was still achieved by experiences of engineers mostly. The work lacked deeply analysis and instruction in theory, especially in designing parallel feedback dielectric oscillator. In this dissertation, firstly oscillating condition and common phase noise analyzing model were introduced; secondly the characteristics of dielectric resonator were analyzed; then the design method of low noise DRO was presented.Finally, a 10GHz low noise dielectric oscillation source was implemented and tested. At the conditions of free oscillation (not in phase locked loop), the single side band phase noise had been achieved -84dBc/Hz@10kHz, -113dBc/Hz@100kHz. -73dBc/Hz@1kHz, -90dBc/Hz@10kHz, -115dBc/Hz@100kHz had been achieved with sampled phase locked loop. Based on the tested data, some improvements on the deficiencies were proposed.