Miniaturized SAW filter structure using unidirectional quadrature IDT couplers

A new single track structure for this unidirectional quadrature IDT coupler has been proposed to reduce a device size. Advantages of the device size and bandwidth for this structure are verified by the calculations and the experiments. The double mode IDTs structure on X-112/spl deg/Y LiTaO/sub 3/ and 190 MHz center frequency are chosen for the experiment.