Saw resonator filter with a multistrip coupler disposed in the resonator gaps

A surface acoustic wave (SAW) filter, comprising:

• a piezoelectric substrate;
• at least two SAW resonators disposed on said piezoelectric substrate, said resonators being symmetrically positioned on two substantially separate tracks, each resonator having a resonant surface acoustic wave structure including a transducer having two conductive portions, the conductive portions including a plurality of interdigitated fingers, the conductive portions being separated from each other by a centrally positioned resonator gap, and being positioned with respect to said resonator gap;
• and
• a multistrip coupler, disposed on said piezoelectric substrate, for acoustically coupling said resonators, said multistrip coupler including a plurality of parallel conductive strips, said conductive strips having an equal spacing between said strips which is substantially equal to a spacing between the equally spaced interdigitated fingers, wherein at least portions of said plurality of said conductive strips are extended between each corresponding resonator gap.

A radio, comprising:

• a radio receiver means for receiving communication signals, said receiver means including a surface acoustic wave structure, comprising:
• at least two SAW resonators being positioned on two substantially separate and parallel tracks, each resonator having a resonant surface acoustic wave structure including at least two conductive portions with a plurality of equally spaced interdigitated fingers, said conductive portions being separated from each other by a resonator gap;
• and
• a multistrip coupler, disposed on said piezoelectric substrate, for acoustically coupling said resonators including a plurality of equally spaced parallel conductive strips extending between each corresponding resonator gap, the multistrip coupler having opposing sides, said conductive strip being spaced to provide an omni-directional coupling between said resonators such that there is an acoustic propagation track from the opposing sides of said multistrip coupler along the conductive portions of the resonators.