Patent ID: 8179211
Filing Date: 2012-05-15
Classification: H03H

Abstract:
1. A RF filter comprising: at least one substrate, a first sub-filter on the substrate comprising a series resonator and a first parallel resonator in a first parallel branch, a second parallel resonator in a second parallel branch, and a third parallel resonator in a third parallel branch, the parallel branches being connected to a signal path comprising the series resonator; a second sub-filter comprising a dual-mode surface wave elements filter (DMS SAW), connected in series to the first sub-filter in the signal path, a housing comprising a base plate comprising: at least two separate lines on the base plate or in the base plate for connecting ground terminals of the first parallel resonator and of the second sub-filter to at least two different external housing contacts, wherein the ground terminal of the first parallel resonator is contacted directly by via-holes without additional wiring to a first external housing contact of the number of external housing contacts, wherein the ground terminal of the first parallel resonator and a ground terminal of the second parallel resonator are separate from one another and are connected to the first external housing contact, and wherein a ground terminal of the third parallel resonator and the ground terminals of the second sub-filter are connected to a second external housing contact of the number of external housing contacts.