Analysis of through glass via (TGV) noise coupling effect to noise figure of 2.4GHz LNA on glass interposer

Abstract

Through glass via(TGV)-TGV coupling noise could badly affect to glass interposer based 2.5D/3D ICs RF system. RF system specification is specified with RF sensitivity. And RF sensitivity is dominantly determined by LNA noise figure. Normally LNA noise figure is calculated with only device and thermal noise since it assumes no noise coupling is exist. For estimating LNA noise figure degradation by TGV-TGV coupling noise, we proposed modified LNA noise figure equation which includes coupling noise effect. For analysis, we designed 2.4GHz LNA schematic and proposed TGV-TGV coupling structure which includes TGVs and channel lines. And then we analyzed output waveform of the LNA with TGV-TGV noise coupling on time domain and frequency domain when single tone noise is injected to LNA components. Finally we estimated noise figure degradation by single tone switching noise.