An antenna structure with wide bandwidth in a reduced physical space includes a housing, a side wall, and a first feed portion. The housing includes a metal side frame, a metal middle frame, and a metal back board. The side wall is made of metal material. The metal middle frame and the metal back board are coupled to two sides of the side wall, and the metal middle frame is parallel to the metal back board. The metal side frame surrounds the metal back board. The metal side frame defines at least one gap. The metal back board defines a slot. The slot and the at least one gap cooperatively divide at least two radiation portions from the metal side frame. A wireless communication device employing the antenna structure is also provided.

An antenna structure with wide bandwidth in a reduced physical space includes a housing, a side wall, and a first feed portion. The housing includes a metal side frame, a metal middle frame, and a metal back board. The side wall is made of metal material. The metal middle frame and the metal back board are coupled to two sides of the side wall, and the metal middle frame is parallel to the metal back board. The metal side frame surrounds the metal back board. The metal side frame defines at least one gap. The metal back board defines a slot. The slot and the at least one gap cooperatively divide at least two radiation portions from the metal side frame. A wireless communication device employing the antenna structure is also provided.

A radiating system for transmitting and receiving signals in first and second frequency regions includes a radiating structure, a radiofrequency system, and an external port. The radiating structure has first and second isolated radiation boosters coupled to a ground plane layer. A first internal port of the radiating structure is between the first radiation booster and the ground plane layer, and a second internal port is between the second radiation booster and the ground plane layer. A distance between the two internal ports is less than 0.06 times a wavelength of the lowest frequency. The maximum size of the first and second radiation boosters is smaller than 1/30 times the wavelength of the lowest frequency. The radiofrequency system includes two ports connected respectively to the first and the second internal ports of the radiating structure, and a port connected to the external port of the radiating system.

A radiating system for transmitting and receiving signals in first and second frequency regions includes a radiating structure, a radiofrequency system, and an external port. The radiating structure has first and second isolated radiation boosters coupled to a ground plane layer. A first internal port of the radiating structure is between the first radiation booster and the ground plane layer, and a second internal port is between the second radiation booster and the ground plane layer. A distance between the two internal ports is less than 0.06 times a wavelength of the lowest frequency. The maximum size of the first and second radiation boosters is smaller than 1/30 times the wavelength of the lowest frequency. The radiofrequency system includes two ports connected respectively to the first and the second internal ports of the radiating structure, and a port connected to the external port of the radiating system.

An electronic device includes a metal frame, an antenna feeding point, an antenna ground, a feeding branch, a grounding branch, an antenna resonance arm, a variable capacitor, and a control circuit. The antenna resonance arm is a part of the metal frame after segmentation, the antenna feeding point is disposed on the feeding branch, a first connection portion and a second connection portion are disposed on the antenna resonance arm, the feeding branch is disposed between the second connection portion and the antenna ground, the grounding branch is disposed between the first connection portion and the antenna ground, the variable capacitor is disposed on the feeding branch, the variable capacitor is disposed between the antenna feeding point and the second connection portion, and the control circuit is configured to adjust a capacitance of the variable capacitor.

An electronic device includes a metal frame, an antenna feeding point, an antenna ground, a feeding branch, a grounding branch, an antenna resonance arm, a variable capacitor, and a control circuit. The antenna resonance arm is a part of the metal frame after segmentation, the antenna feeding point is disposed on the feeding branch, a first connection portion and a second connection portion are disposed on the antenna resonance arm, the feeding branch is disposed between the second connection portion and the antenna ground, the grounding branch is disposed between the first connection portion and the antenna ground, the variable capacitor is disposed on the feeding branch, the variable capacitor is disposed between the antenna feeding point and the second connection portion, and the control circuit is configured to adjust a capacitance of the variable capacitor.

An electronic device includes a casing, a circuit board and at least one antenna module. The casing has an accommodating space and an inner side wall surrounding the accommodating space. The circuit board is disposed in the accommodating space. Each of the antenna modules includes a first radiator and a second radiator. The first radiator is disposed on the circuit board and adjacent to the inner side wall, and includes a first section, a second section and a third section extending from the first section in opposite directions respectively. The first section includes a feeding end, and the third section includes a grounding end. The second radiator is disposed on the inner side wall. A coupling gap is formed between the first radiator and the second radiator.

An antenna for a Radio Frequency Identification (RFID) transponder, including: terminals for connection with an RFID chip; two or more inductive loops; and one or more resonant structure; wherein the two or more inductive loops and the one or more resonant structure are arranged and configured such that the antenna has two or more lines of symmetry when viewed in a thickness direction of the antenna, and wherein the terminals are located within a centre portion of an overall structure of the antenna.

An antenna includes a first radiator and a first capacitor structure. A first end of the first radiator is electrically connected to a signal feed end of a printed circuit board by means of the first capacitor structure, and a second end of the first radiator is electrically connected to a ground end of the printed circuit board. The first radiator, the first capacitor structure, the signal feed end, and the ground end form a first antenna configured to produce a first resonance frequency. An electrical length of the first radiator is greater than one eighth of a wavelength corresponding to the first resonance frequency, and the electrical length of the first radiator is less than a quarter of the wavelength corresponding to the first resonance frequency.

An antenna includes a first radiator and a first capacitor structure. A first end of the first radiator is electrically connected to a signal feed end of a printed circuit board by means of the first capacitor structure, and a second end of the first radiator is electrically connected to a ground end of the printed circuit board. The first radiator, the first capacitor structure, the signal feed end, and the ground end form a first antenna configured to produce a first resonance frequency. An electrical length of the first radiator is greater than one eighth of a wavelength corresponding to the first resonance frequency, and the electrical length of the first radiator is less than a quarter of the wavelength corresponding to the first resonance frequency.