SAW filter with insertion loss of 2 dB and fractional bandwidth of 30 percent

A very low insertion loss and very wideband SAW filter with ring topology on high electromechanical coupling coefficient substrates is demonstrated in the paper. The insertion loss is 1.9 dB and 3-dB fractional bandwidth is 30%. The filter also shows linear phase characteristic with small size and low passband ripples. The insertion loss is the lowest ever reported with such a wide bandwidth.