Abstract: A filter apparatus includes a filter body including one or more resonator cavities, a casing, wherein the filter body is arranged inside the casing, and at least one flexible fixing member. A first connection area of the at least one flexible fixing member is fixed to the casing and a second connection area of the at least one flexible fixing member is fixed to the filter body. The at least one flexible fixing member is made of material including at least one of metal, polymer, rubber.

Abstract: A filter apparatus includes a filter body including one or more resonator cavities, a casing, wherein the filter body is arranged inside the casing, and at least one flexible fixing member. A first connection area of the at least one flexible fixing member is fixed to the casing and a second connection area of the at least one flexible fixing member is fixed to the filter body. The at least one flexible fixing member is made of material including at least one of metal, polymer, rubber.

Abstract: A filter apparatus includes a first conductive signal line configured to form a first radio frequency resonator; a second conductive signal line configured to form a second radio frequency resonator; a cross-coupling element comprising a first electrode arranged to couple capacitively to the first conductive signal line, a second electrode arranged to couple capacitively to the second conductive signal line, and an electrically conductive signal line coupling the first electrode to the second electrode. The cross-coupling element is bendable with respect to the first conductive signal line and the second conductive signal line to adjust the capacitive coupling.