A microwave switched multiplexer having a bandpass At between frequencies f1 and f2, Δf=f1−f2, the multiplexer comprising n signal channels, where n>1, each signal channel having a signal bandpass at a center frequency within M, the center frequencies of the signal channels being equally spaced apart by Δf/n; each signal channel comprising (a) a switch having first, second and third ports, the switch being adapted to be switched between a transmit position in Which the first port is connected to the second port, a receive position in which the first port is connected to the third port and an off position in which the first port is not connected to either second or third ports; (b) a common line extending from an antenna end to the first port, the common; line ι comprising an input resonator and a center resonator connected together in cascade, the center resonator being coupled between the resonator and the first port.