A mobile device includes an antenna structure, a signal source, a tunable circuit element, and a tuner. The antenna structure includes a radiation element. The tunable circuit element is coupled to the radiation element. The antenna structure and the tunable circuit element are disposed in a clearance region of the mobile device. The tuner has a variable impedance value, and is coupled between the tunable circuit element and the signal source. The tuner and the signal source are disposed in a circuit board region of the mobile device.

A mobile device includes an antenna structure, a signal source, a tunable circuit element, and a tuner. The antenna structure includes a radiation element. The tunable circuit element is coupled to the radiation element. The antenna structure and the tunable circuit element are disposed in a clearance region of the mobile device. The tuner has a variable impedance value, and is coupled between the tunable circuit element and the signal source. The tuner and the signal source are disposed in a circuit board region of the mobile device.

A matching circuit for an antenna of whatever type, includes a ground circuit and a feed circuit. The ground circuit connects a ground terminal of the antenna to a ground voltage, and provides an inductive impedance between the ground terminal and the ground voltage. The feed circuit connects a feed signal to a feed terminal of the antenna. The feed circuit is capable of switching between a first mode and a second mode for respectively providing a first equivalent impedance and a second equivalent impedance between the feed signal and the feed terminal. An associated method is also disclosed.

A matching circuit for an antenna of whatever type, includes a ground circuit and a feed circuit. The ground circuit connects a ground terminal of the antenna to a ground voltage, and provides an inductive impedance between the ground terminal and the ground voltage. The feed circuit connects a feed signal to a feed terminal of the antenna. The feed circuit is capable of switching between a first mode and a second mode for respectively providing a first equivalent impedance and a second equivalent impedance between the feed signal and the feed terminal. An associated method is also disclosed.

In a wireless communication device, an impedance matching circuit includes a first layered coil conductor one end of which is connected to a first I/O terminal, the first layered coil conductor includes loop conductors including a plurality of layers, and a second layered coil conductor one end of which is connected to the other end of the first layered coil conductor and the other end of which is respectively connected to a second I/O terminal, the second layered coil conductor includes loop conductors including a plurality of layers. On the surface of the wireless communication device, first and second terminal electrodes are connected via first and second in-plane conductors and first and second inter-layer conductors to any of the loop conductors of the first and second layered coil conductors. Connection locations of the first and second in-plane conductors to the first and second layered conductors determine the antenna element-side impedance seen by the first and second I/O terminals of the wireless IC chip.

In a wireless communication device, an impedance matching circuit includes a first layered coil conductor one end of which is connected to a first I/O terminal, the first layered coil conductor includes loop conductors including a plurality of layers, and a second layered coil conductor one end of which is connected to the other end of the first layered coil conductor and the other end of which is respectively connected to a second I/O terminal, the second layered coil conductor includes loop conductors including a plurality of layers. On the surface of the wireless communication device, first and second terminal electrodes are connected via first and second in-plane conductors and first and second inter-layer conductors to any of the loop conductors of the first and second layered coil conductors. Connection locations of the first and second in-plane conductors to the first and second layered conductors determine the antenna element-side impedance seen by the first and second I/O terminals of the wireless IC chip.

An antenna device includes a slot, a connecting assembly, a first capacitor and a match circuit. The slot is defined in a shell of the mobile terminal. The slot separates the shell into a first part and a second part, and the first part couples with a mainboard via a feeding point to form a slot antenna. The connecting assembly connects the first part with the second part. The first capacitor couples the first part with the feeding point. The match circuit couples the first part with the feeding point.

An antenna device includes a slot, a connecting assembly, a first capacitor and a match circuit. The slot is defined in a shell of the mobile terminal. The slot separates the shell into a first part and a second part, and the first part couples with a mainboard via a feeding point to form a slot antenna. The connecting assembly connects the first part with the second part. The first capacitor couples the first part with the feeding point. The match circuit couples the first part with the feeding point.

An antenna device includes a slot, a connecting assembly, a first capacitor, a first match circuit, an antenna and a second match circuit. The slot is defined in a shell of the mobile terminal. The slot separates the shell into a first part and a second part. The first part is configured to couple with a mainboard via a first feeding point to form a slot antenna. The connecting assembly connects the first part with the second part. The first capacitor couples the first part and the first feeding point. The first match circuit couples the first capacitor and the first feeding point. The antenna is configured to send a signal through the slot. The antenna is disposed above the mainboard and below the slot and the antenna couples with the mainboard via a second feeding point.

Provided are an antenna and a user equipment. The antenna includes a mainboard PCB 1, a metal frame 2, an antenna radiation element 3, a first and second feeding branch element 31, 32, a grounding element 4, a feeding point 7, and a clearance area 8. The mainboard PCB 1 is connected to the metal frame 2 via grounding element 4; the antenna radiation element 3 is arranged in clearance area 8 located at an upper side of the mainboard PCB 1; the metal frame 2 and the antenna radiation element 3 are arranged on a perimeter of a user equipment to form a user equipment frame, and a first and second gap 21, 22 are provided between metal frame 2 and antenna radiation element 3; and the feeding point 7 is connected to the antenna radiation element 3 via the first and second feeding branch element 31, 32, separately.