Arrangement and method relating to coupling of signals to/from microwave devices

An arrangement for coupling electromagnetic waves into and/or out of a microwave device comprising at least one dielectric resonator including a non-linear dielectric substrate with a high dielectric constant, and a coupling loop, wherein the dimensions of the resonator and the coupling loop are related to the resonant frequency of the resonator, the coupling loop having such a geometry and being arranged in relation to the resonator such that the magnetic field lines provided around the coupling loop match an internal field distribution of at least one mode of the resonator so that only said at least one mode is excited in the resonator, and coupling being provided only for said at least one mode, the coupling loop having a length nearly equal to, or larger than, dimensions of the resonator, and wherein one end of the coupling loop is connected to one of the resonator plates, DC-biasing being applicable through the coupling loop, thus providing for electrical tuning of the resonator.