Filter module with improved linearity response

A radio frequency (RF) module comprising:

• a packaging board configured to receive a plurality of components;
• and
• a filter module implemented on the packaging board, the filter module including an input port configured to receive an RF signal, a first output port configured to be connected to an antenna, a filter disposed along a fundamental signal path extending from the input port to the first output port, and a second output port configured to output a harmonic signal generated in response to the RF signal, the second output port being electrically connected to a point on the fundamental signal path via a harmonic signal path through which the harmonic signal passes, the harmonic signal path including at least one resonating structure configured to improve a linearity response of the filter module, the at least one resonating structure including a plurality of resonators that are electrically connected to each other in anti-series or anti-parallel and disposed on a piezoelectric film, the resonators arranged such that a polarity direction of a first half of the resonators is opposite to a polarity direction of a second half of the resonators when a voltage is applied across the piezoelectric film.

A mobile device comprising:

• an antenna configured to receive a radio frequency (RF) signal;
• and
• a front end system configured to communicate with the antenna, the front end system including a filter module, the filter module including an input port configured to receive an RF signal, a first output port configured to be connected to an antenna, a filter disposed along a fundamental signal path extending from the input port to the first output port, and a second output port configured to output a harmonic signal generated in response to the RF signal, the second output port being electrically connected to a point on the fundamental signal path via a harmonic signal path through which the harmonic signal passes, the harmonic signal path including at least one resonating structure configured to improve a linearity response of the filter module, the at least one resonating structure including a plurality of resonators that are electrically connected to each other in anti-series or anti-parallel and disposed on a piezoelectric film, the resonators arranged such that a polarity direction of a first half of the resonators is opposite to a polarity direction of a second half of the resonators when a voltage is applied across the piezoelectric film.