Contents I. Introduction
Simultaneous switching noise is a primary source of noise in mixed signal systems and is generated by a digital circuit switching and coupling to neighboring circuits [1]–[3]. Simultaneous switching noise coupling between circuits occurs more easily in system-in-package (SiP) designs due to the high density of circuits and components integrated onto a small package substrate [4]. In the case of radio-frequency (RF) and analog circuits, simultaneous switching noise coupling causes serious performance degradation [5]–[7]. Among circuits, the low noise amplifier (LNA) is the most noise-sensitive RF circuit, as it handles weak signals in the microvolt regime. When simultaneous switching noise is coupled to a LNA, it also couples to the LNA output. The weak signal is easily overwhelmed at the output by the coupled simultaneous switching noise, and, as a consequence, LNA performance (such as the noise figure) is degraded. Furthermore, system sensitivity, which is dominated by LNA performance, is also reduced.
