| 摘要 |
<p>1,119,235. Electromechanical filters. SONUS CORP. 8 June, 1965 [9 June, 1964], No. 58946/67. Divided out of 1,119,234. Heading H3U. [Also in Division H1] The bandwidth of a piezo-electric coupling element is controlled by increasing the polarizing voltage to a value beyond that required to polarize the element. It is stated that the bandwidth increases with the voltage so that a desired bandwidth can be obtained by using an appropriate voltage. The method may be applied to a filter and, in particular, to the filter described in Specification 1,119,234. The Specification gives several detailed examples of band-pass characteristics obtained by using various polarizing voltages in the manufacture of filters of the kind referred to above.</p> |
