Multipole monolithic Surface Acoustic Wave (SAW) resonator filters

We have successfully produced four and six pole SAW resonator filters for the first time, to our knowledge. The foundation for future development work has been established through the successful application of a synthesis technique, development of rapid analysis routines, and the application of our single pole resonator design and fabrication techniques to multipole configurations utilizing transducer and reflector coupling. Significant and critical innovations during this program include the techniques, through analysis, of determining the correct isolated pole resonance frequency to effect a synchronously tuned filter, establishment of physical methods for determining and setting these frequencies, and the establishment of a technique for adjusting the coupling of a reflector coupler. The response characteristics attained thus far meet only some of the performance criteria; notably: insertion loss, shape factor, bandwidths, and center frequencies. Problems remain in shaping the passband, improving the rejection level, and reducing leakage. We have outlined the work to be performed in phase 2 which is oriented towards solving these problems.