Abstract: A high-frequency bandwidth amplifying circuit includes a forward channel and a backward channel. An input terminal of the forward channel and an external forward input terminal are connected; an output terminal of the forward channel and a forward output port are connected. An input terminal of the backward channel and an external backward input terminal are connected; an output terminal of the backward channel and a backward output port are connected. The high-frequency bandwidth amplifying circuit further includes a feedback network. The forward channel includes a first operational amplifier and a second operational amplifier. An input terminal of the first operational amplifier is connected to the external forward input terminal; an output terminal of the first operational amplifier is connected to an input terminal of the second operational amplifier; and an output terminal of the second operational amplifier is connected to the forward output port.