Novel Multi-Coupled Line Resonators Replace Traditional Ceramic Resonators in Oscillators/VCOs

Communication systems rely on stable signal source (oscillator/VCO) to maintain phase-locked conditions and ensure transmitted data integrity. Many third and later generation systems incorporate multiple narrowband ceramic coaxial resonator oscillators (CROs) to cover their bandwidth requirement. Ceramic CROs are renowned for their ability to generate high spectral purity signal at RF/microwave frequencies. Unfortunately, CROs 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 MCLR (multi-coupled line resonator) based oscillator/VCO, which is promising alternative of CROs, and supports better noise performance than commercial available high Q (quality factor) ceramic CROs at a fraction of cost