Reliability issues on the novel surface acoustic wave notch filter

A novel surface acoustic wave (SAW) notch filter was fabricated on 128°-rotated YX-cut lithium niobate (LiNbO₃) with a finger width of 8 μm. Then, photolithography and lift-off techniques were applied to make a metal pattern on the LiNbO₃ substrates. Finally, a central frequency of 113.4 MHz, and a 3 dB bandwidth of 0.36 % and the insertion loss S₂₁ of -10.583 dB are obtained. The novel SAW notch filter is a planar filter that has a small volume. It is also a passive device that has no power consumption. The frequency response curve of the novel SAWnotch filters is sharper than RLC notch devices. Another advantage of novel SAW notch filters in communication systems is a sufficient high-power durability. With different electrode materials, this will allow power levels up to 30 dBm. It shows that the novel SAW notch filers have a higher reliability than RLC notch filters with high-power AC input signals. Combining high stability, high stop-band rejection and narrow transition width from pass-band to the stop-band, the novel surface acoustic wave notch filters offer superior performance over other notch devices.