Quasi-Microwave Band Longitudinally Coupled Surface Acoustic Wave Resonator Filters Using ZnO/Sapphire Substrate

The 1.5 and 2.4 GHz range 5IDT-type longitudinally coupled surface acoustic wave (SAW) resonator filters have been developed using ZnO/sapphire substrate. The 1.5 GHz range SAW filter has the minimum insertion loss of 1.0 dB and the relative bandwidth of 2.4% at the insertion loss of 3 dB. The 2.4 GHz range SAW filter has the minimum insertion loss of 1.7 dB and the relative bandwidth of 1.7% at the insertion loss of 3 dB. These filters are suitable for use as RF-stage filters in a personal digital cellular (PDC) system terminal and a wireless local area network (LAN) adapter, respectively.