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.

The present invention provides a common-mode signal absorber, which comprises an impedance-matching network and a common-mode signal reflection circuit. A differential-mode signal is inputted into input ends of the impedance-matching network, and outputted from output ends of the common-mode signal reflection circuit. When a common-mode signal is inputted into the common-mode signal absorber, the common-mode signal reflection circuit is for reflecting the common-mode signal within a specific frequency band. Afterward, the reflection of the common-mode signal within the specific frequency band will be absorbed by an impedance element of the impedance-matching network. Thus, the common-mode signal within the specific frequency band may be absorbed by the impedance-matching network so as to avoid to interfere signals transmitted on a communication system.

A method and apparatus for tuning crosstalk and return loss are provided. In the method and apparatus, a filter tunes return loss caused by a first external terminal and a second external terminal to compensate for a capacitive load induced by sizes of and a proximity between the first and second external terminals. The filter decouples the tuning of the return loss from tuning a magnitude and a phase of a crosstalk between a first transmission line network and a second transmission line network such that the return loss is tuned with minimal impact on the crosstalk.

A method and apparatus for tuning crosstalk and return loss are provided. In the method and apparatus, a filter tunes return loss caused by a first external terminal and a second external terminal to compensate for a capacitive load induced by sizes of and a proximity between the first and second external terminals. The filter decouples the tuning of the return loss from tuning a magnitude and a phase of a crosstalk between a first transmission line network and a second transmission line network such that the return loss is tuned with minimal impact on the crosstalk.

A circuit (290) comprises an RC filter circuit (100), which comprises an ohmic resistor (112) and a capacitor (113). In addition, the circuit (290) comprises a compensation circuit (200), which is designed to provide a compensation current flow (192), which corresponds to a current flow (191) to a load (150).

A circuit (290) comprises an RC filter circuit (100), which comprises an ohmic resistor (112) and a capacitor (113). In addition, the circuit (290) comprises a compensation circuit (200), which is designed to provide a compensation current flow (192), which corresponds to a current flow (191) to a load (150).

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 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 method and apparatus for tuning crosstalk and return loss are provided. In the method and apparatus, a filter tunes return loss caused by a first external terminal and a second external terminal to compensate for a capacitive load induced by sizes of and a proximity between the first and second external terminals. The filter decouples the tuning of the return loss from tuning a magnitude and a phase of a crosstalk between a first transmission line network and a second transmission line network such that the return loss is tuned with minimal impact on the crosstalk.

A method and apparatus for tuning crosstalk and return loss are provided. In the method and apparatus, a filter tunes return loss caused by a first external terminal and a second external terminal to compensate for a capacitive load induced by sizes of and a proximity between the first and second external terminals. The filter decouples the tuning of the return loss from tuning a magnitude and a phase of a crosstalk between a first transmission line network and a second transmission line network such that the return loss is tuned with minimal impact on the crosstalk.