| 摘要 |
<p>A new piezo-electric ceramic composition for resonator in electrical wave-filters are now provided, which essentially consists of a modified or unmodified lead zirconate titanate and, as additives, 1.5 to 4.5% of tungsten oxide (WO3) and 0.1 to 0.5% of chromium oxide (Cr2O3) based on the total weight of the composition, and which shows in combination a low mechanical quality factor (Qm) value of not more than 300, a high electromechanical coupling coefficient, a high dielectric constant, and improved temperature and time stabilities of the resonant frequency for the filter resonator. The wave-filter produced from the new composition exhibits improved group-delay-time characteristics.</p> |
