Active Planar Coupled Resonators Replace Traditional High Q Resonators in Low Phase Noise Oscillators/VCOs

SAW/ceramic resonators are renowned for their ability to generate high spectral purity signal at RF/microwave frequencies. Unfortunately, SAW/ceramic resonators based oscillators have several disadvantages, including a limiting temperature range, limited tuning range, not amenable for fabrication by current integrated circuit (IC) technology, and also sensitive to phase hits. These resonators are custom made for long lead-time and because of tension in crystal structure of the pressed and backed device, tend to cause phase hits in oscillators and synthesizers. This paper discusses the novel approach of active planar coupled resonator (APCR) based voltage-controlled oscillator (VCO), which is viable alternative of traditional high quality factor (Q) resonators and offers low phase noise and phase hits insensitive solution at a fraction of cost