Aspects of this disclosure relate to an interdigital transducer capacitor that includes capacitor fingers with different pitches between pairs of adjacent capacitor fingers. In certain embodiments, the interdigital transducer capacitor and an acoustic wave resonator can be formed of different regions of a piezoelectric layer. Related acoustic wave devices, filters, multiplexers, radio frequency modules, radio frequency systems, wireless communication devices, and methods are disclosed.

A surface acoustic wave resonator device comprises a substrate supporting: a gateable, electrically conducting layer; an interdigital transducer (IDT); a reflector grating that comprises a plurality of electrically separated fingers; a main ohmic contact; and a gate element. The IDT is configured to be connectable to a ground. The conducting layer is configured to be connectable to the ground via the main ohmic contact, while each of said fingers is electrically connected to a lateral side of the conducting layer. This defines a gateable channel, which extends from the fingers to the ground via the conducting layer and the main ohmic contact. The gate element is electrically insulated from the conducting layer. The gate element is configured to allow an electrical impedance of the gateable channel to be continuously tuned by applying a voltage bias to this gate element with respect to the ground, in operation of the device.

The present invention discloses a substrate, an electronic device, and a module. The substrate provided by embodiments comprises a carrier substrate formed of a polycrystalline material, wherein the carrier substrate has a grain density greater than or equal to 1000 grains/mm.sup.2; and a grain boundary volume fraction ranging from 8% to 40%. The disclosed carrier substrate having such a specific grain density achieves high mechanical strength, which reduces the likelihood of chipping due to insufficient strength, thereby ensuring production quality and efficiency.