Filter devices having reduced spurious emissions from lamb waves

A filtering module comprising:

• a packaging substrate;
• a filter die disposed on the packaging substrate and having a common contact, a first signal contact, and a second signal contact, the filter die including a first filter connected between the common contact and the first signal contact and having a first passband, the first filter including a piezoelectric substrate, a surface acoustic wave (SAW) filter formed on a surface of the piezoelectric substrate, a SAW resonator formed on the surface of the piezoelectric substrate and connected in series between the common contact and the SAW filter, and a dielectric film formed over the surface of the piezoelectric substrate and covering the SAW filter and SAW resonator, the dielectric film having a first thickness in a first region corresponding to the SAW filter and a second thickness in a second region corresponding to the SAW resonator, the first thickness being greater than the second thickness, the filter die further including a second filter connected between the common contact and the second signal contact and having a second passband different from the first passband, a center frequency of the second passband being in a range of 1.2 to 1.4 times greater than a center frequency of the first passband;
• and
• a plurality of connection pads disposed on the packaging substrate, the common contact, the first signal contact, and the second signal contact of the filter die being connected to corresponding ones of the plurality of connection pads by respective electrical connectors.