A filter apparatus, which includes a feedback active common-mode filter and a feed-forward active common-mode filter, the feedback active common-mode filter includes a common-mode noise detection component and a first filter circuit, and the feed-forward active common-mode filter includes the common-mode noise detection component and a second filter circuit, where the first filter circuit is connected between the common-mode noise detection component and the device, and performs feedback filtering on a first common-mode noise signal, to obtain a second common-mode noise signal; the common-mode noise detection component is connected between the first filter circuit and the second filter circuit, detects the second common-mode noise signal, and provides the second filter circuit with the second common-mode noise signal; and the second filter circuit is connected between an external power source and the common-mode noise detection component, and performs feed-forward filtering on the second common-mode noise signal.

A filter apparatus, which includes a feedback active common-mode filter and a feed-forward active common-mode filter, the feedback active common-mode filter includes a common-mode noise detection component and a first filter circuit, and the feed-forward active common-mode filter includes the common-mode noise detection component and a second filter circuit, where the first filter circuit is connected between the common-mode noise detection component and the device, and performs feedback filtering on a first common-mode noise signal, to obtain a second common-mode noise signal; the common-mode noise detection component is connected between the first filter circuit and the second filter circuit, detects the second common-mode noise signal, and provides the second filter circuit with the second common-mode noise signal; and the second filter circuit is connected between an external power source and the common-mode noise detection component, and performs feed-forward filtering on the second common-mode noise signal.

An acoustic-wave device with active calibration mechanism is provided. The acoustic-wave device with active calibration mechanism includes at least one adjustable acoustic-wave duplexer, a frequency discriminator and a control circuit. The adjustable acoustic-wave duplexer has a first terminal point, a second terminal point and a third terminal point. The adjustable acoustic-wave duplexer includes a TX filter, an RX filter, a first loop switch and a second loop switch. The first loop switch is used for conducting a first loop. The second loop switch is used for conducting a second loop. The control circuit adjusts the operating frequency of the TX filter according to a first loop calibration signal. The control circuit adjusts the operating frequency of the operating frequency of the RX filter according to the second loop calibration signal.

A filter apparatus, which includes a feedback active common-mode filter and a feed-forward active common-mode filter, the feedback active common-mode filter includes a common-mode noise detection component and a first filter circuit, and the feed-forward active common-mode filter includes the common-mode noise detection component and a second filter circuit, where the first filter circuit is connected between the common-mode noise detection component and the device, and performs feedback filtering on a first common-mode noise signal, to obtain a second common-mode noise signal; the common-mode noise detection component is connected between the first filter circuit and the second filter circuit, detects the second common-mode noise signal, and provides the second filter circuit with the second common-mode noise signal; and the second filter circuit is connected between an external power source and the common-mode noise detection component, and performs feed-forward filtering on the second common-mode noise signal.