<p>The invention provides an active circulator for a microwave system. Said microwave system comprises at least one front-end arrangement. Each front-end arrangement comprises 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 ampiifier 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 wherein each front-end arrangement comprises one active circulator. Said active circulator comprises the power ampiifier function, the low noise amplifier function and the circulator function of directing a signal flow, said three functions integrated into one module. The invention also provides a method to manufacture the active circulator.</p>
