Abstract: Apparatus and methods for balun transformer circuits within electronic devices are provided. In certain embodiments, balun transformer circuits are used for reduction of an impedance of a differential load line of a differential power amplifier.

Abstract: A radio frequency ladder filter comprises a plurality of series bulk acoustic wave (BAW) resonators electrically connected in series between an input and an output, at least one BAW resonator connected between a node between adjacent ones of the plurality of series BAW resonators and ground, at least one shunt resonator element including an inductor and a capacitor in series and electrically coupled to ground between the input and a first of the plurality of series resonators, and at least one last shunt resonator element including an inductor and a capacitor in series and electrically coupled to ground between the output and a last of the plurality of series resonators.

Abstract: An acoustic wave filter assembly having reduced on-die capacitance and improved isolation for high-frequency applications. The acoustic wave filter assembly includes a filter port, an antenna port, an acoustic wave filter connected between the filter port and the antenna port, one or more ground pins connected between the filter port and the antenna port, and a metallic guard ring extending around the acoustic wave filter assembly. At least one of the one or more ground pins is connected to the metallic guard ring. A diplexer, multiplexer, radio-frequency module and wireless device are also provided.

Abstract: A filter module has a first terminal, a second terminal, and at least one filter disposed along each signal path extending from the first terminal to the second terminal. The filter can include a plurality of series resonators and a plurality of shunt resonators disposed between the series resonators and a ground configured to enhance power ruggedness of the filter module. A matching circuit coupled to the filter performs impedance matching of the filter.

Abstract: Examples of the disclosure include a wireless device comprising a power amplifier configured to output a balanced amplified signal, an antenna configured to transmit and receive signals, a balun coupled to the power amplifier and the antenna, and being configured to receive the balanced amplified signal and output, based on the balanced amplified signal, an unbalanced amplified signal to the antenna, and at least one capacitor coupled in series between the power amplifier and the balun.