Double mode surface wave resonators
AssigneeNorthern Telecom Limited
InventorsJohn C. B. Saw, Thomas P. Cameron, Mark S. Suthers, John J. Nisbet, Samuel A. Tiller
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Abstract
A double mode surface wave resonator comprises two IDTs (inter-digital transducers), arranged side by side between reflection gratings, on a surface of a piezoelectric substrate to provide for coupling of surface waves therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT. One or each of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator. The electrodes of the IDTs can be arranged in spatial synchronism with adjacent fingers of the reflection gratings to reduce spurious longitudinal modes.
Claims23
A surface wave resonator comprising:
- a piezoelectric substrate;
- and
- two IDTs (inter-digital transducers) arranged side by side on a surface of the substrate with a common rail therebetween, so that surface waves are coupled between the IDTs, each IDT having interleaved electrodes extending from the common rail and from a respective outer rail, the outer rails providing signal connections to the resonator;
- wherein at least one of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator.
A double mode surface wave resonator comprising two IDTs (inter-digital transducers), arranged side by side between reflection gratings, on a surface of a piezoelectric substrate to provide for coupling of surface waves therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT, wherein at least one of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator.
A double mode surface wave resonator comprising two IDTs (inter-digital transducers), arranged side by side between reflection gratings comprising grounded fingers, on a surface of a piezoelectric substrate to provide for coupling of surface waves therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT, wherein electrodes of at least one of the IDTs are arranged in spatial synchronism with adjacent fingers of the reflection gratings.
A double mode surface wave resonator comprising two IDTs (inter-digital transducers), arranged side by side between reflection gratings, on a surface of a piezoelectric substrate to provide for coupling surface surfaces therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT, wherein the electrodes of at least one of the IDTs are divided into two groups with a resonant cavity between the groups, and the electrodes of each group are arranged in spatial synchronism with adjacent fingers of the adjacent reflection grating.
Dependencies are inferred from the claim text.