High frequency ladder type piezo-electric filter with differently poled series and parallel resonators

摘要

A ladder type piezo-electric filter comprising series piezo-electric resonators and parallel piezo-electric resonators having improved second harmonic mode, high resonance response and anti-resonance impedance near 1-7 MHz, for use in communication applications requiring filter shaving resonator dimensions less than 5 mm and operating frequencies in excess of 455 kHz.