An LC filter includes an input terminal, an output terminal, a multilayer body, plate electrodes, connection electrodes connecting the plate electrodes, capacitor electrodes, and a inductor vias. Each of the capacitor electrodes opposes the plate electrode. One end of an inductor via is connected with the input terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode. An inductor via is connected between the plate electrode and a capacitor electrode. An inductor via is connected between the plate electrode and a capacitor electrode. One end of an inductor via is connected with the output terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode.

An LC filter includes an input terminal, an output terminal, a multilayer body, plate electrodes, connection electrodes connecting the plate electrodes, capacitor electrodes, and a inductor vias. Each of the capacitor electrodes opposes the plate electrode. One end of an inductor via is connected with the input terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode. An inductor via is connected between the plate electrode and a capacitor electrode. An inductor via is connected between the plate electrode and a capacitor electrode. One end of an inductor via is connected with the output terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode.

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 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.

The, present application provides a filtering circuit and a. TV antenna amplifier, the filtering circuit includes a switching module, and the switching module includes a control unit and at least two filtering units. The present application switchably render one of the at least two filtering units conductive through the control unit, and filter the signals of different frequencies in the input signals through the at least two filtering units, so that different filtering units can be switched according to the filtering requirements of the frequency signal in different regions, which makes it a wide application range.

An adaptive radio frequency including an input, an output, at least one fixed passive inductor and at least one variable active inductor connected between the input and the output.

In a resonant device, a first via electrode and a second via electrode connect a first plane electrode and a third plane electrode. A third via electrode and a fourth via electrode connect the first plane electrode and a second plane electrode. When the first plane electrode is seen in plan view in a normal direction of the first plane electrode, a first imaginary line connecting the first via electrode and the second via electrode intersects with a second imaginary line connecting the third via electrode and the fourth via electrode.

In a resonant device, a first via electrode and a second via electrode connect a first plane electrode and a third plane electrode. A third via electrode and a fourth via electrode connect the first plane electrode and a second plane electrode. When the first plane electrode is seen in plan view in a normal direction of the first plane electrode, a first imaginary line connecting the first via electrode and the second via electrode intersects with a second imaginary line connecting the third via electrode and the fourth via electrode.

The invention relates to a tunable, silicon-based negative-resistance circuit (10, 30) and to an active filter (50) for E-band frequencies (60 to 90 GHz). A base of a transistor (11) is connected to an on-chip inductive transmission line (13) which has a length of approximately a quarter-wavelength at a frequency of 83.5 GHz. The transmission line connects a DC voltage source (14) to the base terminal of the transistor (11) in order to bias the base. Another DC voltage source (15) is connected to the collector of the transistor (11) to bias the transistor. A capacitor (16) operatively bypasses or decouples the voltage source (15) in order to shunt high frequencies or alternating current (AC) signals to ground. The emitter terminal of the transistor (11) is connected to ground through a resistor (18) to limit the collector current (l.sub.e). The circuit gives rise to improved quality factor of resonators.

An electronic component includes a multilayer body including dielectric layers, a circuit pattern, and band-shaped conductor patterns. The circuit pattern includes a conductor pattern that is disposed inside the multilayer body and defines an inductor. The band-shaped conductor patterns are grounded and cover a portion of a shield surface. An internal surface is located between the circuit pattern and an upper surface. On a shield surface, a non-shielded area is provided which is not covered with any of the band-shaped conductor patterns, and through which magnetic flux generated from the inductor is able to pass.