Abstract: A radio frequency (RF) module includes a multilayer substrate having dielectric layers and metallization layers that include one or more circuit elements. The metallization layers are located between the dielectric layers. The RF module also includes a symmetric transmission input associated with the multilayer substrate, an RF element on the multilayer substrate to provide RF functionality, and a balun integrated in the substrate behind the symmetric transmission input.

Abstract: A duplexer that includes an input filter (Rx filter), an output filter (Tx filter), and one or more of an isolation line and a delay line is disclosed. The Rx and Tx filters are microwave (MW) resonators and include continuous, internally metallized holes in a ceramic body. The ceramic body includes a metal coating substantially covering the external surfaces of the ceramic body except for an end face and one or more recesses on a bottom side of the ceramic body. An output of the Rx filter on the bottom side of the ceramic body is electrically connected to a balun. The ceramic body has a first height in an area of the Tx filter and a second height in an area of the Rx filter, the second height being less than the first height.

Abstract: It is proposed that a balun implemented in LTCC technology shall be incorporated into the microwave ceramic body of a duplexer in such a way that the total overall height of the duplexer is not increased. To do so, the height of the ceramic body in the range of the RX filter is reduced to an area corresponding to the size of the LTCC balun. A compact component is thus obtained with no change in the properties of the Tx filter; this component can supply a symmetrical output signal without any increase in volume for the RX path.

Abstract: A radio frequency (RF) module includes a multilayer substrate having dielectric layers and metallization layers that include one or more circuit elements. The metallization layers are located between the dielectric layers. The RF module also includes a symmetric transmission input associated with the multilayer substrate, an RF element on the multilayer substrate to provide RF functionality, and a balun integrated in the substrate behind the symmetric transmission input.