GB868186A - Microwave device - Google Patents

Abstract

868,186. Waveguide switches. HUGHES AIRCRAFT CO. July 17, 1959 [Aug. 12, 1958], No. 24708/59. Class 40(8) A microwave switch or phase-changer comprises a waveguide in which is arranged an elongated member of wave-permeable gyromagnetically-resonant material having a longitudinal slot through which pass the tunes of a magnetizing winding. In the switch of Fig. 2 an elongated slab 20 of ferrite having a longitudinal aperture 25 is arranged against or near to the narrow wall of a waveguide 12. A winding 30, situated entirely within the waveguide, provides a magnetic field within the ferrite which is predominantly normal to the broad walls. It is stated that, in the magnetized condition, the ferrite element causes generation of higher-order modes in the waveguide and that coupling between these modes causes reflection of energy. The device does not utilize absorption due to gyromagnetic resonance. Mode coupling may be improved by the use of tuning screws 50 which are stated not to affect propagation in the unmagnetized (closed) state of the switch. Dielectric loading may be used for the same purpose. The device may be used without the tuning screws as a phase-shifter. In another form of phase-shifter (Fig. 5) an elongated ferrite member 29 having a longtitudinal aperture 27 is arranged on the centre line of a broad side of waveguide 12. A winding 30 provides a predominantly axial magnetic field within the element. The phase-shifter may be associated with other devices, e.g. hybrid-T-junctions, to form a switch.