Use of second order information in the auto regressive moving average technique for the design of linear phase SAW filters

The design of small size low loss SAW filter utilizes the concept of single phase unidirectionality where the distributed reflectors are superimposed on top of a normal SAW interdigital transducer. The impulse responses for these filters are synthesized using unit cells comprising of withdrawal weighted reflection and transduction centers. The reflecting DART/EWC structures in the design of SAW filters have so far been used to provide the directivity on the acoustic ports for reducing the insertion loss and pass band ripples. In the present work the reflections arising from the DART/EWC structures are used to synthesize the poles in SAW transducer transfer function for implementing IIR transfer function in SAW technology for reducing the size and improving the pass-band and stop band performance of SAW filters. The work describes the use of mixed first and second order information, in the form of a finite portion of its impulse response {h0, h1, ..., hm} and the autocorrelation sequence {r0, r1,...., rn}.