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 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.

Disclosed is a radio frequency (RF) filter that vertically integrates an acoustic wave filter with an integrated passive device (IPD) filter. The acoustic wave filter provides selectivity at fundamental frequency band while the IPD filter provides rejection at harmonic frequency bands.

A flexible resonant trap circuit is provided that includes a transmission line arranged to include a helical winding that has a first helical winding segment and a second helical winding segment; and a capacitor coupled between the first and second helical winding segments.

A flexible resonant trap circuit is provided that includes a transmission line arranged to include a helical winding that has a first helical winding segment and a second helical winding segment; and a capacitor coupled between the first and second helical winding segments.

A circuit board having excellent reliability of connection between layers while being capable of achieving a compact and low-profile electronic device. In the circuit board has an LC circuit built therein with the use of a glass core having a through hole, a conductor layer formed in the through hole is connected to a wiring pattern formed on one surface of the glass core, and connected to a wiring pattern formed on the other surface of the glass core, with the conduction layer projected from the surface of the glass core. Thus, the area of contact between the conduction layer and the through hole is increased, thus making it possible to prevent the reliability of connection between layers in the through hole from being decreased, even when the glass core is reduced in thickness for achieving a low-profile device.

An electrical filter circuit is disclosed. The circuit includes a first input line and a second input line. A first transmission line is coupled electrically in series at a first node with a first output line, and an inductor is coupled electrically in series between the first input line and the first transmission line. The filter also includes a second transmission line having a first impedance coupled to the first node. The second input line is coupled electrically in series at a second node with a second output line. A third transmission line is coupled to the second node, and a capacitor is coupled electrically in series between the second transmission line and the third transmission line. The first output line has a second impedance that is greater than the first impedance.

An electrical filter circuit is disclosed. The circuit includes a first input line and a second input line. A first transmission line is coupled electrically in series at a first node with a first output line, and an inductor is coupled electrically in series between the first input line and the first transmission line. The filter also includes a second transmission line having a first impedance coupled to the first node. The second input line is coupled electrically in series at a second node with a second output line. A third transmission line is coupled to the second node, and a capacitor is coupled electrically in series between the second transmission line and the third transmission line. The first output line has a second impedance that is greater than the first impedance.

A multilayer wiring substrate and a module having the multilayer wiring substrate, wherein the multilayer wiring substrate has a capacitor with a capacitance value smaller than that of the conventional one. The substrate includes a core substrate and capacitors installed therein. At least one of the capacitors is a first capacitor which includes a lower electrode, a dielectric layer, and an upper electrode. The lower electrode is located closer to the core substrate than the dielectric layer and the upper electrode are. The upper electrode is located farther away from the core substrate than the dielectric layer and the lower electrode are. The lower electrode is entirely disposed on the core substrate. The upper electrode has a first portion and a second portion. The first portion overlaps the dielectric layer and the lower electrode to serve as the first capacitor. The second portion extends from the first portion.

A multilayer wiring substrate and a module having the multilayer wiring substrate, wherein the multilayer wiring substrate has a capacitor with a capacitance value smaller than that of the conventional one. The substrate includes a core substrate and capacitors installed therein. At least one of the capacitors is a first capacitor which includes a lower electrode, a dielectric layer, and an upper electrode. The lower electrode is located closer to the core substrate than the dielectric layer and the upper electrode are. The upper electrode is located farther away from the core substrate than the dielectric layer and the lower electrode are. The lower electrode is entirely disposed on the core substrate. The upper electrode has a first portion and a second portion. The first portion overlaps the dielectric layer and the lower electrode to serve as the first capacitor. The second portion extends from the first portion.