Hybrid filters and more particularly filters having acoustic wave resonators (AWRs) and lumped component (LC) resonators and packages therefor are described. In an example, a packaged filter includes a package substrate, the package substrate having a first side and a second side, the second side opposite the first side. A first acoustic wave resonator (AWR) device is coupled to the package substrate, the first AWR device comprising a resonator. A plurality of inductors is in the package substrate.

A multilayer LC filter includes a magnetic coupling adjustment inductor for at least one LC resonator. The magnetic coupling adjustment inductor includes a line conductor pattern and a first via conductor connected to each other. The line conductor pattern is connected to an intermediate point of a second via conductor, and the first via conductor is connected to a ground conductor pattern. A loop inductor and the magnetic coupling adjustment inductor in the LC resonator for which the magnetic coupling adjustment inductor is provided are magnetically coupled to a loop inductor in another adjacent LC resonator.

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 phase shifter module includes a base material, a common terminal, and individual terminals, the common terminal and the individual terminals being provided at the base material. Inside the base material, phase shifters that are connected between the individual terminals and the common terminal, respectively, are provided. The phase shifters each include a primary coil and a secondary coil that is coupled to the primary coil by magnetic field coupling and define a transformer phase shifter. With this configuration, a phase shifter module for use with SAW filters while reducing or preventing interference among the SAW filters, a multiplexer/demultiplexer that includes the phase shifter module, and a communication apparatus that includes the phase shifter module, are obtained.

A multilayer band pass filter includes first and second LC parallel resonators. The first and second LC parallel resonators include a first inductor and a second inductor, respectively. The first inductor includes a first line conductive pattern, a first via conductive pattern, and a second via conductive pattern. The first line conductive pattern extends in the X-axis direction on a first dielectric layer. The first via conductive pattern and second via conductive pattern extend from the first line conductive pattern toward a second dielectric layer. The second inductor includes a third via conductive pattern extending in the Z-axis direction.

A balun includes a first LC resonator, a second LC resonator, a third LC resonator, and a fourth LC resonator. The second LC resonator is magnetically coupled with the first LC resonator. The fourth LC resonator is magnetically coupled with the third LC resonator and electrically connected between a third terminal and a fourth terminal in parallel with the second LC resonator. Each of the first LC resonator and the second LC resonator has a resonant frequency that is a first resonant frequency. Each of the third LC resonator and the fourth LC resonator has a resonant frequency that is a second resonant frequency higher than the first resonant frequency.

Examples of a capacitive-coupled bandpass filter include a plurality of coupling capacitors connected in series along a signal path extending between an input contact and an output contact, a first harmonic suppression notch circuit configured to provide a first harmonic suppression notch in a frequency response of the capacitive-coupled bandpass filter, and a second harmonic suppression notch circuit configured to provide a second harmonic suppression notch in the frequency response of the capacitive-coupled bandpass filter. The first harmonic suppression notch circuit includes a first pair of series L/C resonators connected in shunt between the signal path and a reference potential, and the second harmonic suppression notch circuit includes a second pair of series L/C resonators connected in shunt between the signal path and the reference potential.

A filter circuit that secures the steepness from a pass range to an attenuation range while maintaining a wide-band transmission characteristic and a filter device including this filter circuit are formed. A filter circuit includes a first filter and a second filter. The first filter is a filter including an LC circuit in which a first frequency band is a pass band and a frequency band not higher than the first frequency band is an attenuation band. The second filter is a filter that attenuates a second frequency band within the first frequency band by using an attenuation pole produced by a resonance or an antiresonance of an acoustic wave resonator. Further, the first filter is placed closer to an antenna terminal than the second filter.

A filter circuit includes: a first element that is a first capacitor or a first inductor connected in series between input and output terminals; a second element that is connected in parallel to the first element between the input and output terminals, is a second inductor when the first element is the first capacitor, and is a second capacitor when the first element is the first inductor; a third element that is connected in parallel to the first element and in series with the second element between the input and output terminals, is a third inductor when the first element is the first capacitor, and is a third capacitor when the first element is the first inductor; and an acoustic wave resonator having a first end coupled to a first node between the second element and the third element and a second end coupled to a ground terminal.

The present application provides an LTCC band-pass filter, including a shell and a filtering assembly. The shell includes a top wall and a bottom wall. The filtering assembly includes a first layer, two second layers respectively overlapped on two opposite sides of the first layer, two third layers respectively overlapped on two sides of the two second layers far away from the first layer, and a fourth layer sandwiched between one of the second layers and the third layers. The first layer is served as an inductance L. The second layer is served as a grounding capacitor C. The second layer and the first layer are coupled together to form an LC resonance unit. The third layer is connected with the ground, and is served as a shielding layer of the LTCC band-pass filter.