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 multilayer electronic device may include a plurality of dielectric layers and a signal path having an input and an output. An inductor may include a conductive layer formed on one of the plurality of dielectric layers and may be electrically connected at a first location with the signal path and electrically connected at a second location with at least one of the signal path or a ground. The inductor may include an outer perimeter that includes a first straight edge facing outward in a first direction and a second straight edge parallel to the first straight edge and facing outward in the first direction. The second straight edge may be offset from the first straight edge by an offset distance that is less than about 500 microns and less than about 90% of a first width of the inductor in the first direction at the first straight edge.

The present invention relates to a radio frequency filter employing a notch structure, wherein the notch structure is a dual notch structure which comprises: a C notch structure formed in a predetermined region at a partition between two cavities to be cross-coupled; and an L notch structure formed together with the C notch structure in a predetermined region at a partition between two cavities.

An apparatus and method for a frequency based integrated circuit that selectively filters out unwanted bands or regions of interfering frequencies utilizing one or more tunable notch or bandpass filters or tunable low or high pass filters capable of operating across multiple frequencies and multiple bands in noisy RF environments. The tunable filters are fabricated within the same integrated circuit package as the associated frequency based circuitry, thus minimizing R, L, and C parasitic values, and also allowing residual and other parasitic impedance in the associated circuitry and IC package to be absorbed and compensated.

An apparatus and method for a frequency based integrated circuit that selectively filters out unwanted bands or regions of interfering frequencies utilizing one or more tunable notch or bandpass filters or tunable low or high pass filters capable of operating across multiple frequencies and multiple bands in noisy RF environments. The tunable filters are fabricated within the same integrated circuit package as the associated frequency based circuitry, thus minimizing R, L, and C parasitic values, and also allowing residual and other parasitic impedance in the associated circuitry and IC package to be absorbed and compensated.

A diplexer includes a first filter circuit including a first loop inductor defining a first loop plane and a second loop inductor defining a second loop plane, a second filter circuit adjacent to the first filter circuit, and a first via hole conductor that electrically connects an input/output terminal, the first filter circuit and the second filter circuit to each other. The first loop plane faces the second loop plane while protruding beyond the second loop plane in a first direction. The first via hole conductor is provided relative to the first loop inductor in a second direction from the first loop plane toward the second loop plane, and is superposed with a portion of the first loop plane that protrudes beyond the second loop plane when viewed in the second direction.

A wiring board with a filter circuit includes an insulating base, a conductor pattern, and a filter circuit. The conductor pattern is provided on the insulating base and defines the filter circuit. The insulating base includes an intermediate member, and first through third end members connected to the intermediate member. A first external connection terminal is provided on the first end member, and is disposed on a first end of the conductor pattern in the signal transmission direction. A second external connection terminal is provided on the second end member, and is disposed on a second end of the conductor pattern in the signal transmission direction. A first ground connection terminal that grounds the filter circuit is provided on the intermediate member. A second ground connection terminal that grounds the filter circuit is provided on the third end member.

A method of constructing an RF filter comprises designing an RF filter that includes a plurality of resonant elements disposed, a plurality of non-resonant elements coupling the resonant elements together to form a stop band having a plurality of transmission zeroes corresponding to respective frequencies of the resonant elements, and a sub-band between the transmission zeroes. The non-resonant elements comprise a variable non-resonant element for selectively introducing a reflection zero within the stop band to create a pass band in the sub-band. The method further comprises changing the order in which the resonant elements are disposed along the signal transmission path to create a plurality of filter solutions, computing a performance parameter for each of the filter solutions, comparing the performance parameters to each other, selecting one of the filter solutions based on the comparison of the computed performance parameters, and constructing the RF filter using the selected filter solution.

A band pass filter includes parallel resonators. An inductor of a first parallel resonator at an intermediate stage is divided into a first inductor and a second inductor connected in parallel with each other. The first inductor and an inductor of a second parallel resonator are in magnetic coupling with each other, and the second inductor and an inductor of a third parallel resonator are in magnetic coupling with each other.

An electronic component includes a second inductor including a second inductor conductor that includes a first coupling portion electrically coupled to a second capacitor conductor and a second coupling portion electrically coupled to a second ground conductor, and when viewed in a plan view from a lamination direction, a first region surrounded by a first inductor conductor and the second inductor conductor is smaller in area than a second region surrounded by a third inductor conductor layer and the second inductor conductor, and a second region forming portion, which is included in the second inductor conductor and surrounds the second region, and a first region forming portion, which is included in the second inductor conductor and surrounds the first region, are electrically coupled in series in this order on a path from the first coupling portion to the second coupling portion.