The invention discloses a low-frequency low-
noise tuning amplification
system, which relates to the technical field of low-frequency communication and comprises a control isolation
driving circuit, a controllable attenuator group, a single-
tuned filter and a low-
noise amplifier, the input end of the control isolation
driving circuit is connected with a
control signal, the first output end of the control isolation
driving circuit is connected with the first input end of the single
tuned filter through the controllable attenuator group, and the control isolation driving circuit is used for carrying out
signal attenuation on the first path of
control signal to obtain an attenuated
control signal; the second output end of the control isolation driving circuit is connected with the second input end of the single
tuned filter; the single tuned filter is used for isolating the attenuated control
signal and performing
gain amplification, and performing
gain amplification according to the second path of control
signal to obtain a tuned output signal; and the low-
noise amplifier is used for amplifying the tuned output signal. According to the invention, through the controllable attenuator, amplification saturation when signals and noise are too large is prevented; the single tuned filter has
signal amplification gain and out-of-
band rejection capability, so that the anti-interference performance of the low-frequency receiving front end is effectively improved; the
digital control signal is isolated by controlling the isolation drive circuit, the influence of noise introduced by an external digital circuit is eliminated, and the anti-interference capability is improved.