Improved sidelobe performance of cosine series functions

The cosine series functions are used extensively for SAW filter design with noniterative techniques. This paper presents improved sidelobe levels of t hese functions by rigorous application of criteria for minimizing the sidel obe peaks. An improvement of 2 dB in sidelobe levels is achieved with respe ct to the earlier results. A new approach is presented to determine the coe fficients of these functions uniquely, which reduces the number of simultan eous equations to be solved to N-1 compared to N equations required to be s olved in the earlier method.