Abstract: Cavity filter with comb-line structure having a steep-flanked flanked pass-band. To obtain this steep flank, rejectors are positioned in the vicinity of the access bars of the filter, orthogonally to the teeth of the comb-line structure. The best results are obtained for the flanks corresponding to the high frequencies of the pass-band, namely with rejectors tuned to frequencies higher than the center frequency of the pass-band.

Abstract: Microwave circuits, namely the circuits relating to the transmission-reception part and to the filtering of the microwave transceiver, are mounted on one and the same multilayer printed circuit and their electromagnetic insulation comprises, firstly, elements of the printed circuit such as conductive tracks on one of the faces of the printed circuit, metallized holes drilled in the tracks and close to one another so as to fulfil the role of an electromagnetic barrier and, at least in the case of some of them, a conductive plate and, secondly, attached elements with, especially, a thick metal lattice surmounted by a lid, the lattice resting on the conductive tracks.

Abstract: This balanced high-frequency mixer is formed around a circuit of the "Balun" type. Though realized for operation in a frequency range from about 1 GHz to 10 GHz, the dielectric substrate SUB used is chosen from the high-loss dielectric materials such as epoxy glass thus permitting to distinctly reduce its cost price. Printed on the substrate is an adapting circuit by partly covered microstrip lines L.sub.1, L.sub.2, L.sub.1 by a semi-rigid coaxial cable section CC, L.sub.2 by a conductor line section CA having the same diameter and the same length as the coaxial cable. The performance of a mixer of this type is comparable to that of a 6 .lambda./4 mixer with clearly less cumbersomeness, of the order of that of a de Lange coupler.