公开(公告)号：CA2343885A1

公开(公告)日：2000-05-04

申请号：CA2343885

申请日：1999-10-26

Applicant: EPCOS AG

Inventor： ROSLER ULRIKE ,  RUILE WERNER ,  BAUER THOMAS ,  KOVACS GUNTER

IPC: H03H9/02 ,  H03H9/145 ,  H03H9/64

Abstract: The aim of the invention is to reduce scattering losses during transmission of a surface acoustic wave signal. To this end, the transition between two surface acoustic wave structures set off from each other is configured in su ch a way that the finger period in the area of transition is reduced and that t he finger period in the area of transition constantly varies.

公开(公告)号：CA2325434A1

公开(公告)日：1999-09-30

申请号：CA2325434

申请日：1999-03-22

Applicant: EPCOS AG

Inventor： JOHANNES THOMAS ,  BAIER THOMAS ,  BAUERNSCHMITT ULRICH ,  ROSLER ULRIKE ,  ALI-HACKL MARKUS ,  FREISLEBEN STEFAN

IPC: H03H9/145 ,  H03H9/00 ,  H03H9/02 ,  H03H9/64

Abstract: The present invention relates to a surface-wave acoustic filter having a capacitive and inductive cross-talk which is compensated between adjacent and interdigitated input and output transformers. These transformers (20; 23) are divided into partial transformers (d, d'; e, e') and the guidance of their pads (24, 25; 26, 27) is modified so that the magnetic couplings between adjacent partial transformers have opposite flow directions (H, H') and so that the total magnetic flow induced is equal to zero. The partial transformers are mounted in series or in parallel so that during a symmetrical operation, the cross-talk capacities between adjacent pads and transformer surfaces are compensated at the corresponding gate.