Abstract: The band widening circuit consists of a section of microstrip with adjustable characteristic impedance connected in series with an adjustable capacitor both connected to the three interleaved conductive pattern of the circulator. The preferred mode consists of a microstrip with air as dielectric and a conductive plate movable with respect to the conductive strip in the shape of a spiral. The capacitor is a conductive plunger movable in a conductively coated recess of a substrate for the conductive strip of the microstrip line section.

Abstract: In a circulator using strip technology a high thermal conductivity through the piled up parts is obtained by use of heat conductive insulating grease layers between the parts which include a solid machined metal cap surrounding the gyromagnetic pellets and broad banding circuits between the ports and earthed contacts on the strip substrate, the capacitor of which uses said cap as an electrode. The outside of said cap is cylindrical, the inside hexagonal.

Abstract: A high level broadband VHF isolator using surface propagation made of the waves comprises two gyromagnetic slabs on both sides of a planar metal sheet acting as a double mode transformer or wave launcher between the two terminals of the isolator and the gyromagnetic medium and magnetizing means. The width of the mode transformer is smaller than that of the slabs and radiating slots are provided along at least one side parallel to the propagation direction. The magnetizing field value corresponds to the gyromagnetic resonance at the mid-frequency of the operating band in the neighborhood of the slots and lower elsewhere. Magnetic means are provided to compensate for the temperature variation of the ferrite properties.