A Single-Inductor Dual-Band VCO in a 0.06mm2 5.6GHz Multi-Band Front-End in 90nm Digital CMOS

Software-defined multi-standard radios are emerging solutions for future mobile applications. Expensive scaled CMOS processes are readily used as a technology enabler to provide adequate performance. The high implementation cost of circuits in such processes is justified by the added functionality of the circuits, however it also drives the desire for low-area solutions in standard digital CMOS. For example, low-area inductor-less LNAs take advantage of the high ft of scaled CMOS. Unfortunately, stringent phase noise requirements make inductors unavoidable in VCOs. This leads to solutions with area-demanding multiple- inductor synthesizers or spur-hazardous multiply-and-divide sections to cover the wide frequency range required for multi- standard receivers. In this work, we demonstrate a low-area multi-standard direct downconversion receiver front-end that uses a single-inductor dual-band VCO and is implemented in 90 nm digital CMOS.