Typical thermo-acoustic pulses are characterized by 50kHz–500kHz bandwidth and weak amplitudes (around 5–50Pa) and thus require low-noise piezoelectric-based ultrasound sensors (with input-referred noise power spectral density, IRN-PSD, as low as 1–2 nV/√Hz) whose output signal is 1–10...
The traditional RTI noise cannot be integrated to find the total noise, whereas the virtual RTI noise can be integrated. The signal gain can be used to translate between virtual RTI noise and RTO noise for both the integrated noise and noise spectral density values....
3) ENSI (Equivalent Noise Sideband Input) 等效噪音边带输入4) equivalent input noise current 等效输入噪声电流 1. Based on the equivalent circuit model of a two-port optical receiver front-end,the relationship between the equivalent input noise current spectral density and the noise figure is ...