A band-pass filter includes an unbalanced port, a first balanced port, a second balanced port, and first to third resonators provided between the unbalanced port and the first and second balanced ports. The second resonator and the third resonator each are a resonator with both ends open. The second resonator and the third resonator are adjacent to each other in a circuit configuration, and electromagnetically coupled by magnetic coupling as main coupling. The first resonator is provided closer to the second resonator than to the third resonator, and jump-coupled to the third resonator.

A band-pass filter includes an unbalanced port, a first balanced port, a second balanced port, and first to third resonators provided between the unbalanced port and the first and second balanced ports. The second resonator and the third resonator each are a resonator with both ends open. The second resonator and the third resonator are adjacent to each other in a circuit configuration, and electromagnetically coupled by magnetic coupling as main coupling. The first resonator is provided closer to the second resonator than to the third resonator, and jump-coupled to the third resonator.

Described is an apparatus which comprises: a first transmission path for a first frequency band; a second transmission path for a second frequency band different from the first frequency band; a node common to the first and second transmission paths, the node to be coupled to an antenna; and a transmission-zero circuit coupled to the common node.

A band pass filter includes filter circuits, first and second intermediate circuits, and a first capacitor. The first intermediate circuit includes an inductor connected between second and third capacitors. The second intermediate circuit includes an inductor connected between third and fourth capacitors. Resonant circuits included in the filter circuit are connected to ground via a common capacitor. Resonant circuits included in the filter circuit are connected to the ground via a common capacitor. The first capacitor is connected between the first and second intermediate circuits.

A circuitry including a first winding coupled to a second winding; a first terminal coupled to a first end of the first winding; a second terminal coupled to a second end of the first winding, wherein there is an imbalance between the first terminal and the second terminal when a current flows through the first winding; and a third terminal coupled to the second winding, wherein a terminal position of the third terminal along the second winding mitigates the imbalance on the first winding.

A filter unit according to the present invention includes a substrate, capacitors mounted on the substrate, and two inductors. The inductors each include a wire and a core. The core includes two core bodies. The core bodies each have a ring shape and include a wiring hole. The capacitors are disposed between the two core bodies. An opposed section extends from the respective two core bodies to a position opposed to the capacitors C. The opposed section is opposed to all of the plurality of capacitors.

The techniques disclosed herein provide low power, efficient systems, devices and circuits that detect facial movements of a user of a Mixed Reality (MR) device. An example battery operated system includes a pulse driver that generates pulse signals at a set frequency, while operated below the battery voltage. An LC filter receives the pulse signals and generates a transient response based on a capacitance value associated with an antenna. The capacitance of the antenna varies responsive to facial movements of the user based on the varying distance of the antenna to the users skin. A coupling capacitor AC couples the output of the LC filter to other system components, where the AC coupled output of the LC filter includes a detected signal amplitude and a detected signal phase of the LC filter responsive to facial movements of the user.

A wide-bandwidth resonant circuit is provided. In an embodiment disclosed herein, the wide-bandwidth resonant circuit includes a positive resonant circuit coupled in parallel to a negative resonant circuit. The positive resonant circuit and the negative resonant circuit can be configured to collectively exhibit certain impedance characteristics across a wide bandwidth. As a result, it is possible to utilize the wide-bandwidth resonant circuit to support a variety of wide-bandwidth applications, such as in a wide-bandwidth signal filter circuit.

Embodiments described herein provide circuitry employing one or more inductors having an unconventional turn-ratio. The circuitry includes a primary inductor having a first length located on a first layer of an integrated circuit (IC). The circuitry further includes a secondary inductor having a second length located on a second layer of the IC different from the first layer, whereby the second length is greater than the first length, with a ratio between the first and the second lengths corresponding to a non-integer turn-ratio.

A filter circuit includes a branch line coupler and a balun circuit having an input terminal connected to the branch line coupler to receive a signal, a first line connected to the input terminal and having a length comparable to a quarter of an electrical length of one wavelength at a frequency of the signal, a second line connected to the input terminal and having a length comparable to the quarter, a third line connected to the second line and having a length comparable to the quarter, and a fourth line connected to the third line and electromagnetically coupled to the first line, the fourth line having a length comparable to the quarter, wherein an end of the first line and an end of the fourth line are both connected to a ground or open-circuited, or are connected to two respective terminating resistors whose resistance values are equal.