The Investigation of Realization Bandpass Impedance Acoustical Active Filters on Saw

The new method of the designing of active bandpass frequency filters is based on inclusion of one or some SAW interdigital transducers (IDTs) into transistor amplifier cascades as frequency depended circuit's elements is investigated. The different methods of including of one or some IDTs into different circuit's have been investigated. It is theoretically shown that transfer function of such amplifiers can have a form of AF characteristic of bandpass filter but without losses and even with the signal amplification in the pass band and with suppression of outpass band signals no less of 40 dB