DUAL-MODE SURFACE WAVE FILTER WITH IMPROVED SYMMETRY AND INCREASED REVERSE ATTENUATION

The device has at least one acoustic track on a piezoelectric substrate with a number of n first interdigital converters (110,160) as a signal input or output and n+1 second interdigital converters (121,122;171,172) as a signal output or input. The interdigital converters are arranged between at least two reflector structures (131,132) bounding the acoustic track. At least one acoustic track (190) has a central converter split into sub-converters (161,162) symmetrically with respect to the perpendicular to the propagation direction and connected to a housing with connecting pads or pins so as to give symmetrical connection occupancy. Independent claims are also included for the following: the use of the filter in asymmetrical/symmetrical mode and the use in symmetrical/asymmetrical mode.