Test and design considerations for a 4 GHz gated ring oscillator in 65 nm CMOS technology for biomedical UWB applications

This paper describes the practical issues associated with the test and design of an impulse-based ultra wideband (I-UWB) transmitter for biomedical applications. A 4 GHz gated ring oscillator is designed and fabricated in a 65 nm CMOS process as a pulse generator for a pulse-position-modulated I-UWB transmitter. The parasitic effects on-chip and off-chip associated with the test setup are investigated, simulated, and experimentally verified. Modeling of the parasitic effects is developed for an improved accuracy in simulation as well as measurement. Further guidelines for design and packaging are introduced.