The invention discloses a low-
noise amplifier circuit. The low-
noise amplifier circuit comprises an input
coupling network, a first
amplifier element, a first biasing unit, a second amplifier element and a second biasing unit, wherein a front-end circuit and the rear-end first amplifier element are connected by the input
coupling network; the first amplifier element is connected with the input
coupling network and used for amplifying an input
signal; the first biasing unit is connected with the first amplifier element, and used for controlling a quiescent
operating point of the first amplifier element in a linear amplifying zone; the second amplifier element is connected with the first amplifier element and used for amplifying an output
signal of the first amplifier element; the second biasing unit is connected with the second amplifier element, and used for controlling a quiescent
operating point of the second amplifier element in the linear amplifying zone. According to the technical scheme, a high-
input impedance wideband and low-
noise amplifier is adopted, the
wideband amplifier realizes pre-amplifying decoupling through high-
input impedance, provides a wider
frequency band, provides a
low noise coefficient, and supports the application of multi-
nuclear magnetic resonance imaging; the design complexity is reduced, the circuit is convenient to debug, and element materials are saved.