An injection nozzle having a nozzle body defining an injection cavity and at least one curing device integrally formed within the nozzle body. The switching module has a plurality of switches each controlled by an input signal, a first voltage input and a second voltage input, and a signal output. The heat pipe extends between the two engaging portions. An automatic-gain-control amplifier receives the output from the amplifier with the limiting function, and amplifies the input voltage signal to a voltage signal having a constant swing.