Miniature And Low Phase Noise Sampling Phase-locked SIW Oscillator

In modern radar and guidance system,the phase noise and frequency stability of the transmitted signal must be good,so the performance and miniaturization of the local oscillator signal is put forwards.With the rapid development of OCXO technology,we are very easy to obtain high frequency stability,good phase noise and good spurs performance of the reference source.But how to use the reference source succinctly,efficiently and reliably to design microwave phase-locked loops is still a challenge in the design of microwave circuits.Traditional phase-locked loops(PLL)circuit usually adopts the digital phase-locked loops,frequency doubling chain and sampling phase-locked loops to realize the tracking and expansion of the reference source.The digital phase-locked loops can be implemented by all-digital circuits with simple structure,high integration,but the performance is not good enough.The frequency doubling chain can provide better near carrier phase noise,but the integration and noise floor is poor.The sampling phase-locked loops has the best performance,but it is difficult to be miniaturized because of the complexity of the oscillator circuit and the sampling phase-locked circuit.In this paper,the substrate integrated waveguide voltage controlled oscillator(SIWVCO)is used to instead of the dielectric.oscillator voltage controlled oscillator(DRVCO)for improving the traditional sampling phase-locked loops.Meanwhile,the multilayer PCB and MCM technology are combined in the design to reduce the size of the whole circuit.Based on analysis of the SIWVCO principles and circuit structures,the SIWVCO circuit is optimized and designed with high integration and low phase noise by using circuit model and the electromagnetic field simulation firstly.Then sampling PLL oscillator and sampling circuit are designed with multilayer PCB process and MCM technology.Finally,the testing results show the SIWVCO circuit achieves phase noise of-111dBc/Hz@1KHz,-120dBc/Hz@10KHz,-116dBc/Hz@100KHz,-130dBc/Hz@1MHz with the 12GHz center frequency.