From: A new portable ELF Schumann resonance receiver: design and detailed analysis of the antenna and the analog front-end
Block description
Noise figure (dB) at 10 Hz
Preamplifier
11.76
Low-pass and notch filter
49.02
Double notch filter
45.89
Double low-pass filter
57.18
High-pass filter
36.71
Voltage gain amplifier
27.77 to 104.62