Abstract: This application provides example antennas and example base stations. One example antenna includes a reflection panel, a radiating element, and a resonator group. The resonator group is disposed between the reflection panel and the radiating element. The resonator group includes a first resonator, a second resonator, and a third resonator. The third resonator has a first connection portion and a second connection portion that are located at at least one open-circuit end. The first resonator is coupled to the first connection portion. The second resonator is coupled to the second connection portion. The third resonator is further coupled to the radiating element, and a signal may be transmitted between the third resonator and the radiating element. The first resonator is configured to transmit a signal in a first frequency band. The second resonator is configured to transmit a signal in a second frequency band.

Abstract: The present disclosure relates to antennas, communication devices, and communication systems. One example antenna includes a plurality of coupled resonators. The plurality of resonators are disposed on a side of a reflection plate. The plurality of resonators may have symmetry, and a first resonator in the plurality of resonators includes a plurality of portions with different extension directions.

Abstract: Embodiments provide a filtering device, to effectively simplify assembly and tuning processes. The filtering device includes: a housing, including an inner cavity; a resonant conductor, having a resonance function, and disposed inside the inner cavity; and a pressing element, having one end disposed on the housing and another end suspended, and facing a position of an open-circuit end of the resonant conductor. A distance between the pressing element and the resonant conductor is changeable when the pressing element is pressed or drawn to adjust a resonant frequency. The filtering device provided in various embodiments is applicable to a plurality of communications devices for selecting a signal frequency.

Abstract: Embodiments provide a filtering device, to effectively simplify assembly and tuning processes. The filtering device includes: a housing, including an inner cavity; a resonant conductor, having a resonance function, and disposed inside the inner cavity; and a pressing element, having one end disposed on the housing and another end suspended, and facing a position of an open-circuit end of the resonant conductor. A distance between the pressing element and the resonant conductor is changeable when the pressing element is pressed or drawn to adjust a resonant frequency. The filtering device provided in various embodiments is applicable to a plurality of communications devices for selecting a signal frequency.

Abstract: Embodiments provide a filtering device, to effectively simplify assembly and tuning processes. The filtering device includes: a housing, including an inner cavity; a resonant conductor, having a resonance function, and disposed inside the inner cavity; and a pressing element, having one end disposed on the housing and another end suspended, and facing a position of an open-circuit end of the resonant conductor. A distance between the pressing element and the resonant conductor is changeable when the pressing element is pressed or drawn to adjust a resonant frequency. The filtering device provided in various embodiments is applicable to a plurality of communications devices for selecting a signal frequency.

Abstract: Embodiments provide a filtering device, to effectively simplify assembly and tuning processes. The filtering device includes: a housing, including an inner cavity; a resonant conductor, having a resonance function, and disposed inside the inner cavity; and a pressing element, having one end disposed on the housing and another end suspended, and facing a position of an open-circuit end of the resonant conductor. A distance between the pressing element and the resonant conductor is changeable when the pressing element is pressed or drawn to adjust a resonant frequency. The filtering device provided in various embodiments is applicable to a plurality of communications devices for selecting a signal frequency.