Fast switching reciprocal ferrite phase shifter

摘要

A fast switching ferrite phase shifter is disclosed featuring both reciprocal operation and fast switching speeds. Reciprocal operation in transmit and receive modes is achieved by employing two latching, toroidal non-reciprocal phase shifters (100,102); one for transmitting and one for receiving. The exemplary embodiment utilizes input and output circulating devices which include a Faraday rotator (108,110) and septum polarizer (104,106) for appropriately routing signals through one or the other of the phase shifters (100,102) depending upon the direction of input signal propogation. The phase shifter (100,102) achieves fast switching since the latching, toroidal, non-­reciprocal phase shifters (100,102) are transversely magnetized devices and are disposed entirely within a waveguide (101) so that the generated magnetic field is confined entirely within the waveguide. The phase shifters (100,102) do not intersect the waveguide walls and, thus, during a switching operation (eg, when the toroid magnetization state is changed due to release of the latching magnetizing current pulse), the magnetic field is not switched through conductive waveguide walls. Accordingly, eddy currents are not induced during a switching operation thereby allowing for fast phase changes to be accomplished (which are not limited due to eddy current delays). An embodiment is disclosed wherein forward and reverse propogating signals may be shifted in phase by individually controllable amounts which may be the same or different. Also, a device is disclosed wherein two waveguide ports are provided on one end (one to be connected to a transmitting means and the other to a receiving means) so that in addition to the phase shifting function a duplexing function is performed.