Passivation layers consisting of sputtered Al/sub 2/O/sub 3/ have been deposited onto SAW devices for the purpose of reducing the incidence of shorts. A coupling-of-modes model was used with one-port resonators, coupled resonator filters and test structures. The passivation layer stiffens the surface, with a velocity increase proportional to (t//spl lambda/), where t is the passivation layer thickness. Attenuation is increased slightly, producing a 0.25 dB increase in the loss of a one-port resonator at 314 MHz. The effect on reflectivity is minimal, and of much lesser importance to the designer.
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机译：为了减少短路的发生，已将由溅射的Al / sub 2 / O / sub 3 /组成的钝化层沉积在SAW器件上。模式耦合模型与单端口谐振器，耦合谐振器滤波器和测试结构一起使用。钝化层使表面变硬，速度增加与（t // spl lambda /）成比例，其中t是钝化层的厚度。衰减略有增加，在314 MHz时，单端口谐振器的损耗增加0.25 dB。对反射率的影响极小，对设计者而言重要性要小得多。
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