X-Band Low Phase Noise Oscillator Based on Hybrid SIW Cavity Resonator

Abstract

In this paper, a compact X-band low phase noise oscillator based on a hybrid SIW cavity resonator is presented. This proposed resonator is composed of a circular waveguide cascaded by two rectangular waveguides. Two pairs of holes are embedded into the resonator to improve the Q-factor. Owing to the existence of discontinuous metal side walls, the fundamental mode $\mathbf{TM}_{110}$ of the circular waveguide can be applied to design the oscillation frequency of the oscillator. The fabricated oscillator has been demonstrated to oscillate at 9.5 GHz. The phase noise is less than −112.84 dBc/Hz at 100 kHz offset with 1.67 dBm output power, exhibiting the figure of merit (FOM) of −202.06 dBc/Hz.