A flip-chip integrated circuit, IC, comprising: a semiconductor die , comprising: at least one semiconductor layer ; a plurality of metal layers for providing interconnections to the at least one semiconductor layer; an aperture layer comprising an input signal transmission aperture configured to pass an input radio-frequency (RF) signal therethrough, and an output signal transmission aperture configured to pass an output RF signal therethrough; and at least one back end-of-line interconnect layer disposed between the at least one semiconductor layer and the aperture layer, the at least one back end-of-line interconnect layer, comprising: an input transmission line configured to transmit the input RF signal through the input signal transmission aperture; and an output transmission line configured to receive the output RF signal through the output signal transmission aperture; and a plurality of conductive bumps interconnected to at least one of the plurality of metal layers , the plurality of conductive bumps and the aperture layer defining an interior resonator cavity ; the interior resonator cavity configured to receive the input RF signal from the input transmission line through the input signal transmission aperture, resonate the input RF signal to generate the output RF signal comprising a filtered RF signal of the input RF signal, and couple the output RF signal on the output transmission line through the output signal transmission aperture. a semiconductor die , comprising: at least one semiconductor layer ; a plurality of metal layers for providing interconnections to the at least one semiconductor layer; an aperture layer comprising an input signal transmission aperture configured to pass an input radio-frequency (RF) signal therethrough, and an output signal transmission aperture configured to pass an output RF signal therethrough; and at least one back end-of-line interconnect layer disposed between the at least one semiconductor layer and the aperture layer, the at least one back end-of-line interconnect layer, comprising: an input transmission line configured to transmit the input RF signal through the input signal transmission aperture; and an output transmission line configured to receive the output RF signal through the output signal transmission aperture; and at least one semiconductor layer ; a plurality of metal layers for providing interconnections to the at least one semiconductor layer; an aperture layer comprising an input signal transmission aperture configured to pass an input radio-frequency (RF) signal therethrough, and an output signal transmission aperture configured to pass an output RF signal therethrough; and at least one back end-of-line interconnect layer disposed between the at least one semiconductor layer and the aperture layer, the at least one back end-of-line interconnect layer, comprising: an input transmission line configured to transmit the input RF signal through the input signal transmission aperture; and an output transmission line configured to receive the output RF signal through the output signal transmission aperture; and an input transmission line configured to transmit the input RF signal through the input signal transmission aperture; and an output transmission line configured to receive the output RF signal through the output signal transmission aperture; and a plurality of conductive bumps interconnected to at least one of the plurality of metal layers , the plurality of conductive bumps and the aperture layer defining an interior resonator cavity ; the interior resonator cavity configured to receive the input RF signal from the input transmission line through the input signal transmission aperture, resonate the input RF signal to generate the output RF signal comprising a filtered RF signal of the input RF signal, and couple the output RF signal on the output transmission line through the output signal transmission aperture. <EOS>