First to fourth filters of an electronic component are provided in a manner that a first path from the first filter to the second filter includes a second path from the third filter to the fourth filter and is also longer than the second path in a circuit configuration. First to fourth inductors of the first to fourth filters are arranged in a manner that an opening of the first inductor and an opening of the third inductor face each other, an opening of the second inductor and an opening of the fourth inductor face each other, and a pair of the second inductor and the fourth inductor is adjacent to a pair of the first inductor and the third inductor.

A variable frequency filter includes a series arm resonant circuit and first and second parallel arm resonant circuits. The series arm resonant circuit is connected between a first connection terminal and a second connection terminal. The first parallel arm resonant circuit is connected to the first connection terminal side of the series arm resonant circuit. In the first parallel arm resonant circuit, a piezoelectric resonator and a variable capacitor are connected in series to each other. The second parallel arm resonant circuit is connected to the second connection terminal side of the series arm resonant circuit. In the second parallel arm resonant circuit, a piezoelectric resonator and a variable capacitor are connected in series to each other. The impedance of the piezoelectric resonator is lower than the impedance of the piezoelectric resonator. The series arm resonant circuit includes a characteristic adjusting capacitor at the first connection terminal side.

Embodiments include apparatuses, methods, and systems with cross-coupling noise reduction in circuits. In embodiments, a circuit may include a common inductor and a negatively coupled inductor pair connected or coupled between the first inductor and a first load and a second load. The negatively coupled inductor pair may include a first and a second inductor. The first inductor may be connected or coupled to the first load and the second inductor may be connected or coupled to the second load to reduce cross-coupling noise between the first load and the second load. Examples of passive structures that may be used to implement the circuit are also described. Other embodiments may also be described and claimed.

In a noise filter circuit, a coupling loop part having a capacitor which is connected to both a positive electrode side input loop line and a negative electrode side output loop line is mounted on a dielectric substrate in a state where a positive electrode side input line and a positive electrode side input end part are connected, a positive electrode side output line and a positive electrode side output end part are connected, a negative electrode side input line and a negative electrode side input end part are connected, and a negative electrode side output line and a negative electrode side output end part are connected.

A laminated composite electronic device has a circuit including a coil and a capacitor within a laminate having a plurality of conductor layers laminated with an insulating layer interposed between the respective ones of the conductor layers. The device includes a coil conductor arranged on a first conductor layer and forming part of the coil, and a pair of capacitor electrodes for forming the capacitor, one of which is arranged on a second conductor layer such that the one capacitor electrode laps over the coil conductor when viewed from a laminating direction of the laminate, wherein the coil conductor forms part of the coil, and simultaneously serves as the other of the pair of capacitor electrode for forming part of the capacitor.

A multilayer filter includes dielectric layers, a first terminal, a second terminal, a first inductor, a second inductor, and first to fifth capacitors. In a stacking direction of the dielectric layers, at least one of a first air-core portion defined by the first inductor and a second air-core portion defined by the second inductor includes, in a region from the first inductor layer to the second inductor layer, a region enabling magnetic flux to pass therethrough without being obstructed by the first to fifth capacitors and the third inductor.

A noise filter includes a filter device and a filter retainer. The filter device includes a device unit having at least one capacitor provided therein, an input side lead wire extending from the device unit, an output side lead wire extending from the device unit, and a ground connection portion provided on the device unit. The filter device forms the noise filter that uses a mutual inductance between the input side lead wire and the output side lead wire. The filter retainer has a holding structure configured to maintain an arrangement of the input side lead wire and the output side lead wire. The arrangement forms an overlapping section in which the lead wires are closely opposed to each other. The noise filter may be attached to a harness.

Reflectionless low-pass, high-pass, band-pass, band-stop, all-pass, and all-stop filters, as well as a method for designing such filters is disclosed, along with a method of enhancing the performance of such filters through the use of sub-networks to further modify and improve the frequency response. These filters preferably function by absorbing the stop-band portion of the spectrum rather than reflecting it back to the source, which has significant advantages in many different applications. The sub-networks preferably offer additional degrees of freedom by which the leakage through the parent filter may be cancelled or reinforced to alter cutoff sharpness, stop-rejection, or other measures of performance.

Reflectionless low-pass, high-pass, band-pass, band-stop, all-pass, and all-stop filters, as well as a method for designing such filters is disclosed, along with a method of enhancing the performance of such filters through the use of sub-networks to further modify and improve the frequency response. These filters preferably function by absorbing the stop-band portion of the spectrum rather than reflecting it back to the source, which has significant advantages in many different applications. The sub-networks preferably offer additional degrees of freedom by which the leakage through the parent filter may be cancelled or reinforced to alter cutoff sharpness, stop-rejection, or other measures of performance.

A low pass filter includes a first via-hole conductor connected to a first end portion of a first inductor and a third end portion of a second inductor and extending to another side in a lamination direction with respect to a second end portion of the first inductor and a fourth end portion of the second inductor, and a first capacitor electrically connected in parallel with at least a portion of the first inductor and a portion of the second inductor and defined by a first capacitor conductor layer. The low pass filter allows the interval between attenuation poles to be easily adjusted.