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: This application provides an antenna and a communication device, and relates to the field of communication technologies, to resolve a problem that the antenna cannot effectively balance a narrow beam width and a small height of a cross section. In the antenna provided in this application, the beam width of the first radiating element can be effectively narrowed by configuring the first conductive part, and the height of the cross section of the antenna is not significantly increased.

Abstract: This disclosure provides a feed network, an antenna apparatus, and a communication device. A main portion is disposed with a first electric-conductor and a second electric-conductor. In addition, two branch portions are disposed, one end of a first branch portion is electrically connected to the first electric-conductor, and one end of a second branch portion is electrically connected to the second electric-conductor. In this way, when two radiation parts in a same polarization direction of a radiating element are electrically connected to the first branch portion and the second branch portion respectively, a transmission structure of the feed network may feed two radio frequency signals, for example, two equi-amplitude phase-inverted radio frequency signals, into the two radiation parts of the radiating element respectively. The feed network in this embodiment of this application has a simple line, so that space occupied by the feed network in the antenna apparatus is reduced.

Abstract: The present disclosure relates to dual-band antennas and antenna arrays. One example dual-band antenna includes a first radiating element and a second radiating element that are disposed on a reflection plate. An operating frequency band of the first radiating element is a first frequency band, and an operating frequency band of the second radiating element is a second frequency band. A minimum frequency of the first frequency band is greater than a maximum frequency of the second frequency band. The first radiating element includes a first feeding apparatus and a first radiator unit, the first feeding apparatus includes a coupling structure coupled to the first radiator unit, and the first feeding apparatus is used for coupled feeding for the first radiator unit by using the coupling structure.

Abstract: A multi-band antenna system and a method for controlling inter-band interference in the multi-band antenna system are provided. The multi-band antenna system includes at least one first radiating element and at least one second radiating element. An operating frequency band of the first radiating element is higher than an operating frequency band of the second radiating element. Each first radiating element includes a grounding structure, a balun, and at least two radiation arms. One end of the balun is electrically connected to the at least two radiation arms. The balun includes at least one conductive structure. The balun is configured to: after obtaining a differential mode signal, input the differential mode signal to the grounding structure using the at least one conductive structure. The differential mode signal is a signal obtained by the balun by sensing a signal from the second radiating element in a differential mode manner.

Abstract: A multi-band antenna system and a method for controlling inter-band interference in the multi-band antenna system are provided. The multi-band antenna system includes at least one first radiating element and at least one second radiating element. An operating frequency band of the first radiating element is higher than an operating frequency band of the second radiating element. Each first radiating element includes a grounding structure, a balun, and at least two radiation arms. One end of the balun is electrically connected to the at least two radiation arms. The balun includes at least one conductive structure. The balun is configured to: after obtaining a differential mode signal, input the differential mode signal to the grounding structure using the at least one conductive structure. The differential mode signal is a signal obtained by the balun by sensing a signal from the second radiating element in a differential mode manner.