Phase Noise Suppression System Based on High-Q Dielectric Resonator

This presentation reports a novel phase-noise suppression system that reduces phase-noise of a 1.6GHz oscillator down to -163dBc/Hz at 10kHz offset. The system utilizes a high-efficiency Frequency Discriminator (FD) based on a high-Q Dielectric Resonator (DR). The system employs two feedback loops: a main phase-noise suppression loop and an auxiliary loop. The main loop is based on the feedback phase-noise cancelation technique and it provides phase-noise suppression at the offsets greater than several kilohertz. Meanwhile, the auxiliary loop is used to lock the FD to the reference oscillator frequency. The FD operates at the fourth harmonic of the reference signal that allows considerable reduction in physical size of the DR cavity and of the entire system. In order to maintain both the high efficiency and low residual noise, the FD incorporates a novel DR coupling structure that comprises a varactor based network to control the FD carrier suppression level.