Abstract: A microwave resonator comprising a hollow tube comprising an electrically conductive tube wall which defines a tube bore, the tube extending along a length axis from a first end to a second end; a first electrically conductive closing plate closing the first end of the tube, the first electrically conductive closing plate comprising at least one coupling slot extending therethrough; a second electrically conducting closing plate closing the second end of the tube, the second electrically conductive closing plate comprising at least one coupling slot extending therethrough; a plurality of dielectric resonant pucks, each puck comprising first and second end faces and a side wall extending therebetween, each puck being dimensioned such that when in the tube its dominant mode is a doubly degenerate mode; the pucks being arranged within the tube bore spaced apart from each other and the closing plates, each puck being arranged centered on the length axis and its side wall abutting the tube wall such that there is

Abstract: A microwave resonator comprising a hollow tube comprising fan electrically conductive tube wall which defines a tube bore, the tube extending along a length axis from a first end to a second end; a first electrically conductive closing plate closing the first end of the tube; a second electrically conductive closing plate closing the second end of the tube; a plurality of dielectric resonant pucks, each puck comprising first and second end faces and a side wall extending therebetween, each puck being dimensioned such that its dominant mode is a doubly degenerate mode; the pucks being arranged within the tube bore spaced apart from each other and the closing plates, each puck being arranged with its end faces normal to the length axis and centered on the length axis and its side wall abutting the tube wall such that there is no air gap between the puck and tube wall which extends from one end face to the other of the puck, the puck adjacent to the first closing plate being termed the input puck; each puck bein

Abstract: A microwave resonator comprising a hollow tube comprising a plurality of electrically conductive wall faces which together define a tube wall defining a tube bore, the tube extending along a length axis from a first end to a second end; the tube wall having an N fold rotational symmetry about the length axis where 2<N<10; a first electrically conductive covering plate covering the first end of the tube; a second electrically conductive covering plate covering the second end of the tube; a dielectric puck comprising first and second end faces and a side wall extending therebetween, the puck being dimensioned such that when in the tube bore its dominant resonant mode is a doubly degenerate mode; the puck being arranged in the tube bore spaced apart from the covering plates with its end faces normal to the length axis and centered on the length axis; the puck being spaced apart from the tube wall by a plurality N of electrically conductive spacer blocks, the spacer blocks being spaced equally around the le

Abstract: A microwave resonator comprising a hollow tube comprising an electrically conductive tube wall which defines a tube bore, the tube extending along a length axis from a first end to a second end; a first electrically conductive closing plate closing the first end of the tube, the first electrically conductive closing plate comprising at least one coupling slot extending therethrough; a second electrically conducting closing plate closing the second end of the tube, the second electrically conductive closing plate comprising at least one coupling slot extending therethrough; a plurality of dielectric resonant pucks, each puck comprising first and second end faces and a side wall extending therebetween, each puck being dimensioned such that when in the tube its dominant mode is a doubly degenerate mode; the pucks being arranged within the tube bore spaced apart from each other and the closing plates, each puck being arranged centered on the length axis and its side wall abutting the tube wall such that there is

Abstract: A microwave resonator comprising a hollow tube comprising a plurality of electrically conductive wall faces which together define a tube wall defining a tube bore, the tube extending along a length axis from a first end to a second end; the tube wall having an N fold rotational symmetry about the length axis where 2<N<10; a first electrically conductive covering plate covering the first end of the tube; a second electrically conductive covering plate covering the second end of the tube; a dielectric puck comprising first and second end faces and a side wall extending therebetween, the puck being dimensioned such that when in the tube bore its dominant resonant mode is a doubly degenerate mode; the puck being arranged in the tube bore spaced apart from the covering plates with its end faces normal to the length axis and centered on the length axis; the puck being spaced apart from the tube wall by a plurality N of electrically conductive spacer blocks, the spacer blocks being spaced equally around the le

Abstract: A microwave resonator comprising a hollow tube comprising fan electrically conductive tube wall which defines a tube bore, the tube extending along a length axis from a first end to a second end; a first electrically conductive closing plate closing the first end of the tube; a second electrically conductive closing plate closing the second end of the tube; a plurality of dielectric resonant pucks, each puck comprising first and second end faces and a side wall extending therebetween, each puck being dimensioned such that its dominant mode is a doubly degenerate mode; the pucks being arranged within the tube bore spaced apart from each other and the closing plates, each puck being arranged with its end faces normal to the length axis and centered on the length axis and its side wall abutting the tube wall such that there is no air gap between the puck and tube wall which extends from one end face to the other of the puck, the puck adjacent to the first closing plate being termed the input puck; each puck bein

Abstract: A tuneable bandpass filter includes a plurality of coupled resonators. A common structure of the filter includes at least one common coupling or one common resonator. An upper loop includes first and second end resonators coupled together by a signal path and further includes at least one further signal path extending between end resonators. The further signal path includes at least one further resonator with the end resonators being coupled to the common structure. A lower loop includes first and second end resonators coupled together by a signal path and further includes at least one further signal path extending between end resonators. The further signal path includes at least one further resonator with the end resonators being coupled to the common structure.

Abstract: A tuneable bandpass filter comprising a plurality of coupled resonators, the filter comprising a common structure comprising at least one common coupling or one common resonator; an upper loop comprising first and second end resonators coupled together by a signal path, the loop further comprising at least one further signal path extending between end resonators, the further signal path comprising at least one further resonator, the end resonators being coupled to the common structure; a lower loop comprising first and second end resonators coupled together by a signal path, the loop further comprising at least one further signal path extending between end resonators, the further signal path comprising at least one further resonator, the end resonators being coupled to the common structure; the resonators being coupled together such that the bandpass filter can be divided into a low pass sub filter and a high pass sub filter, one of the sub filters being arranged to receive the output of the other.