A coaxial mirror is provided for reflecting an electromagnetic signal. The mirror includes an outer pipe, an inner pipe, and first and second rods. The outer pipe extends between input and output ports, with closed initial and final terminals disposed at their respective ports. The inner pipe extends between a closed fore end and an open aft end. The inner pipe is coaxially disposed between the initial and final terminals within the outer pipe. The first rod, coaxially disposed within the outer pipe, extends from the input port to the fore end. The second rod, coaxially disposed within the inner pipe, extends from downstream of the fore end to the output port. Preferably, the first and second pipes are cylindrical tubes. Preferably, fluoropolymer fills the annular region between the inner and outer pipes, and fluoropolymer foam fills the inner pipe. Preferably, the first pipe has an electrically conductive inner surface, the second pipe has electrically conductive inner and outer surfaces, and the first and second rods have conductive surfaces. A first embodiment includes a conductor, coaxially disposed within the inner pipe, that extends from the fore end to the second rod. In a second embodiment, the second rod is hollow, and is preferably filled with the foam.