A circuit, comprising: at least two segments of an integrated circuit waveguide filter, the at least two segments coupled by an iris; each segment of the integrated circuit waveguide filter further comprises; a top conductive layer for the respective segment of the integrated circuit waveguide filter; a bottom conductive layer for the respective segment of the integrated circuit waveguide filter, the top and bottom conductive layers (130, 134) of the respective segment coupled via a plurality of couplers (140, 140a, 360) that form an outline of the waveguide filter for the respective segment; a dielectric substrate layer disposed between the top conductive layer and the bottom conductive layer of the respective segment of the integrated circuit waveguide filter, the dielectric substrate layer for the respective segment having a relative permittivity, ε r that affects the tuning of the integrated circuit waveguide filter; characterised in that the circuit further comprises at least one substrate tunable via (160, 160a) comprising a tunable material disposed within the dielectric substrate layer for the respective segment, the tunable via (160, 160a) coupled to a set of electrodes, the set of electrodes enable a voltage to be applied to the tunable material within the tunable via (160, 160a) to change the relative permittivity of the dielectric substrate layer for the respective segment and to enable tuning the frequency characteristics of the integrated circuit waveguide filter for the respective segment; and at least one iris tunable via (160, 160a) comprising a tunable material disposed within the iris coupling the respective segments, the tunable via (160, 160a) coupled to a set of electrodes, the set of electrodes enable a voltage to be applied to the tunable material within the tunable via (160, 160a) of the iris to change the relative permittivity of the iris and to enable tuning the frequency characteristics of the integrated circuit waveguide filter. at least two segments of an integrated circuit waveguide filter, the at least two segments coupled by an iris; each segment of the integrated circuit waveguide filter further comprises; a top conductive layer for the respective segment of the integrated circuit waveguide filter; a bottom conductive layer for the respective segment of the integrated circuit waveguide filter, the top and bottom conductive layers (130, 134) of the respective segment coupled via a plurality of couplers (140, 140a, 360) that form an outline of the waveguide filter for the respective segment; a dielectric substrate layer disposed between the top conductive layer and the bottom conductive layer of the respective segment of the integrated circuit waveguide filter, the dielectric substrate layer for the respective segment having a relative permittivity, ε r that affects the tuning of the integrated circuit waveguide filter; characterised in that the circuit further comprises at least one substrate tunable via (160, 160a) comprising a tunable material disposed within the dielectric substrate layer for the respective segment, the tunable via (160, 160a) coupled to a set of electrodes, the set of electrodes enable a voltage to be applied to the tunable material within the tunable via (160, 160a) to change the relative permittivity of the dielectric substrate layer for the respective segment and to enable tuning the frequency characteristics of the integrated circuit waveguide filter for the respective segment; and at least one iris tunable via (160, 160a) comprising a tunable material disposed within the iris coupling the respective segments, the tunable via (160, 160a) coupled to a set of electrodes, the set of electrodes enable a voltage to be applied to the tunable material within the tunable via (160, 160a) of the iris to change the relative permittivity of the iris and to enable tuning the frequency characteristics of the integrated circuit waveguide filter.