Noise figure in UWB systems
Noise figure (NF) is a commonly used system parameter that quantifies the degradation in the signal-to-noise ratio (SNR) as the signal passes through a system. Different from the narrow band systems, the energy of the transmitted signal spread on wide band in the UWB (Ultra Wide Band) systems. The NF is varying in the signal band if a narrow band system NF is used in UWB systems, a more precise NF is needed for UWB systems. Conventional narrow band systems noise analysis methods and their shortcomings are discussed, then an NF that suit for digital UWB systems is described. Take a UWB LNA design for example, the advantage of the UWB NF is demonstrated as a conclusion.