An active circulator for a microwave system. The microwave system includes at least one front-end arrangement. Each front-end arrangement includes a power amplifier function arranged to deliver an amplified output signal via a circulator function to an antenna in a transmit mode. A low noise amplifier function is arranged to amplify an input signal from the antenna via the circulator function in a receive mode. The circulator function is arranged to direct a signal flow between the transmit and receive modes. Each front-end arrangement includes one active circulator. The active circulator includes the power amplifier function, the low noise amplifier function and the circulator function of directing a signal flow. The functions integrated into one module. Also, a method to manufacture the active circulator.