Examples provide a wideband filter structure and apparatus, a radio transceiver, a mobile terminal, and a method for filtering a radio signal. The wideband filter structure (10) for a radio signal comprises a combination of at least one acoustic resonator (12) and at least one analog resonator (14). The acoustic resonator (12) is coupled to the analog resonator (14). The wideband filter structure (10) comprises a further component (16), which is coupled to the combination of the acoustic resonator (12) and the analog resonator (14).

A filter (10) includes two capacitors (C1a and C1b) that are connected in series on a path connecting an input terminal (101a) and an output terminal (102a), an inductor (L2) that is connected in parallel with a series circuit including the two capacitors (C1a and C1b), and a parallel-arm resonator (P1) that is connected between the ground and a node (N) between the two capacitors (C1a and C1b) on the path.

A filter includes: a substrate; input and output terminals located on the substrate; a resonant circuit located in a series pathway between the input and output terminals; a first component including a first inductor, which is electrically connected between a first node in the series pathway and a ground, and mounted in a first region on the substrate; a second component including a second inductor, which is electrically connected between a second node different from the first node in the series pathway and a ground, and mounted in a second region different from the first region on the substrate; and a third component including an acoustic wave resonator, which is electrically connected between a third node between the first and second nodes in the series pathway and a ground, and mounted in a third region between the first and second regions on the substrate.

A filter element is mounted on a module substrate. The filter element includes a ground terminal and a pair of signal terminals. The module substrate includes a ground plane, a ground land, and an inductance adjusting line that connects the ground land to the ground plane. The ground terminal of the filter element is connected to the ground land of the module substrate. The inductance adjusting line includes an in-plane extending portion that extends in an in-plane direction of the module substrate.

In a band pass filter, a signal input into a first terminal is transmitted to a first LC resonator and a second LC resonator in this order and is then output from a second terminal. The band pass filter includes a third inductor and a third capacitor. A first end of the third inductor is electrically connected to the ground. The third capacitor is electrically connected between a second end of the third inductor and a node between the first LC resonator and the second LC resonator.

A band pass filter includes: a first circuit unit including a first series LC resonant circuit disposed between a first terminal and a second terminal; a second circuit unit disposed between the first circuit unit and the second terminal, and including a first parallel LC resonant circuit; and a third circuit unit disposed between the first terminal and a ground, and including a second series LC resonant circuit, wherein a resonant frequency of the first circuit unit is in a pass band.

A low pass filter includes a first inductor, a second inductor magnetic-field-coupled to the first inductor, a third inductor, and a first capacitor. The first inductor is electrically connected between a first port and an intermediate node, being a node to which the second inductor is electrically connected, between the first inductor and the second port. The second inductor is electrically connected between the intermediate node and a ground terminal. The third inductor is electrically connected between the intermediate node and the second port, and a first parallel resonant circuit is defined by the third inductor and the first capacitor. The first inductor and the second inductor are coupled to each other in such a relationship that a negative inductance is generated between the intermediate node and the third inductor due to magnetic field coupling between the first inductor and the second inductor.

A filter includes: a substrate; input and output terminals located on the substrate; a resonant circuit located in a series pathway between the input and output terminals; a first component including a first inductor, which is electrically connected between a first node in the series pathway and a ground, and mounted in a first region on the substrate; a second component including a second inductor, which is electrically connected between a second node different from the first node in the series pathway and a ground, and mounted in a second region different from the first region on the substrate; and a third component including an acoustic wave resonator, which is electrically connected between a third node between the first and second nodes in the series pathway and a ground, and mounted in a third region between the first and second regions on the substrate.

An apparatus is provided. The apparatus includes an electronic circuit for processing a differential signal. A device including an electronic circuit may include a first inductor and a second inductor that process a differential signal, a first circuit connected to the first inductor in parallel, a second circuit connected to the second inductor in parallel, and lines connecting the first inductor and the first circuit, the lines being disposed to pass through an area defined by the first inductor and the second inductor. The first inductor and the second inductor have symmetrical differential structures.

A band pass filter includes: a first circuit unit including a first series LC resonant circuit disposed between a first terminal and a second terminal; a second circuit unit disposed between the first circuit unit and the second terminal, and including a first parallel LC resonant circuit; and a third circuit unit disposed between the first terminal and a ground, and including a second series LC resonant circuit, wherein a resonant frequency of the first circuit unit is in a pass band.