Surface acoustic wave filters
AssigneesClarisay, Inc., Sawcom Limited
InventorsJames Edward Flowers, James Heighway
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Abstract
Filter structures are described consisting of a plurality of individual surface acoustic wave (SAW) resonators formed of inter-digitated metallic combs on a common piezoelectric substrate. Areas of metallisation (1, 2, 3, 4) between the combs provide means to connect the filter in a circuit, e.g. in a mobile telephone unit to act as a filter with a passband in the 800 to 2200 MHz range. The individual SAW resonators differ from one another and are interconnected in ladder and/or balanced bridge arrangements.
Claims8
A multiple single port leaky SAW resonator filter comprising a piezoelectric substrate having deposited thereon a plurality of SAW resonators, each resonator being formed of an inter-engaged comb-like pattern of metallic coating on the substrate, and each individual resonator being not identical and being connected together, via the metallic coating on the substrate, to form a ladder or balanced bridge or combination ladder and balanced bridge filter structure.
Dependencies are inferred from the claim text.