Abstract: A cavity-backed slot antenna system provided in this disclosure is installed in a housing of an electronic device and includes a metal cavity, a supporting element, an antenna device, a conductive post, and a coupling metal part. The metal cavity is in the housing and includes an opening and a closed surface opposite to each other. A slot is on the closed surface. The supporting element is in the metal cavity. The antenna device is in the metal cavity and on the supporting element, to expose one side surface of the antenna device. The antenna device includes a feed source. The conductive post penetrates the antenna device and connects to the metal cavity. The coupling metal part is in the housing and close to the opening of the metal cavity, so that the coupling metal part is close to and corresponds to the feed source of the antenna device.

Abstract: An antenna system includes: a plurality of antennas; a switching unit, having a plurality of switches, wherein each of the plurality of switches and the corresponding antenna are in a conducting state or in a non-conducting state; a communication unit, connected with each of the plurality of switches of the switching unit, and coupled with the antennas, wherein the communication unit receives a reference value group of the corresponding antenna from the switch in the conducting state; and a control unit, connected with the switching unit and the communication unit, wherein the control unit receives the reference value group from the communication unit, and compares the reference value group with an threshold, to determine whether the reference value group conforms to a pre-determined condition or not, and outputs a restarting instruction to restart the switching unit when the reference value group does not satisfy the pre-determined condition.

Abstract: An antenna system includes: a plurality of antennas; a switching unit, having a plurality of switches, wherein each of the plurality of switches and the corresponding antenna are in a conducting state or in a non-conducting state; a communication unit, connected with each of the plurality of switches of the switching unit, and coupled with the antennas, wherein the communication unit receives a reference value group of the corresponding antenna from the switch in the conducting state; and a control unit, connected with the switching unit and the communication unit, wherein the control unit receives the reference value group from the communication unit, and compares the reference value group with an threshold, to determine whether the reference value group conforms to a pre-determined condition or not, and outputs a restarting instruction to restart the switching unit when the reference value group does not satisfy the pre-determined condition.

Abstract: A tunable antenna including a first radiating element, a second radiating element, a connection circuit and a switch circuit is provided. The first radiating element includes a coupling portion and a first feeding portion. The second radiating element includes a second feeding portion, a grounding portion and a radiation portion. The grounding portion is electrically connected to a ground plane, and the radiation portion surrounds the coupling portion to form a first coupling gap and the second coupling gap. The connection circuit is electrically connected to the radiation portion and a state of the connection circuit is changed according to a control signal, so as to adjust a length of the resonant path of the radiation portion. A feeding signal is transmitted to the first feeding portion or the second feeding portion by the switch circuit.

Abstract: An antenna device is provided. The antenna includes a feeding end, a grounding end, a loop metal portion and a protruded metal portion. The grounding end is electrically connected to a ground plane. The loop metal portion extends from the feeding end to the grounding end to form a loop antenna structure. The protruded metal portion is electrically connected to the loop metal portion, wherein the distance between the protruded metal portion and the grounding end is shorter than the distance between the protruded metal portion and the feeding end.

Abstract: A tunable antenna including a first radiating element, a second radiating element, a connection circuit and a switch circuit is provided. The first radiating element includes a coupling portion and a first feeding portion. The second radiating element includes a second feeding portion, a grounding portion and a radiation portion. The grounding portion is electrically connected to a ground plane, and the radiation portion surrounds the coupling portion to form a first coupling gap and the second coupling gap. The connection circuit is electrically connected to the radiation portion and a state of the connection circuit is changed according to a control signal, so as to adjust a length of the resonant path of the radiation portion. A feeding signal is transmitted to the first feeding portion or the second feeding portion by the switch circuit.

Abstract: A tunable antenna includes a ground plane, a first radiation unit and a second radiation unit. The first radiation unit includes a feeding portion and a coupling portion. The feeding portion is electrically connected to a signal source. The second radiation unit surrounds a part of the coupling portion and includes a grounding end and a switch unit. The grounding end is electrically connected to the ground plane. The switch unit is electrically connected to the grounding end and the ground plane selectively.

Abstract: An antenna device is provided. The antenna includes a feeding end, a grounding end, a loop metal portion and a protruded metal portion. The grounding end is electrically connected to a ground plane. The loop metal portion extends from the feeding end to the grounding end to form a loop antenna structure. The protruded metal portion is electrically connected to the loop metal portion, wherein the distance between the protruded metal portion and the grounding end is shorter than the distance between the protruded metal portion and the feeding end.